Head to head · Answer search · October 2026 research run

Grounding with Bing Search vs Liner Search MCP

Grounding with Bing Search scores 63.7 (B) on agent readiness against Liner Search MCP's 43.4 (E), and leads in 5 of 7 scored categories. Both do answer search.

Best web search APIs for AI agents · All 326 search comparisons

Which one, for what

Grounding with Bing Search B

Best for Teams already building on Foundry Agent Service who want cited answers from Bing without handling a search key.

Ahead on

  • Reliability, 68 against 50
  • Schema & documentation, 68 against 45
  • Security & auth, 79 against 35
  • Maintenance & community, 80 against 45
  • Transparency & trust, 66 against 34

Watch for

The Bing tools never return raw results to developers, only a model-written answer with citation links

Liner Search MCP E

Best for Agents that need cheap cited search across the web and scholarly sources, with optional deep research reports.

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

No free tier found

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Security & auth Grounding with Bing Search +44

Grounding with Bing Search 79

Callers authenticate to the Foundry project with Microsoft Entra ID tokens and RBAC roles (Foundry User to run agents, Foundry Project Manager to add connections), with just-in-time Contributor through Entra PIM for provisioning. The Bing resource key sits in a project connection and the agent never holds it. No key in a URL (28 of 30). The tools only read. Custom Search confines grounding to configured public domains, and an admin can turn web search off for a whole subscription. There is no per-agent read-only toggle to set, since the tools have no write path (15 of 20). The web search page tells developers to treat web search results as untrusted input and to keep secrets and personal data out of prompts, and the tool best practices page says the same of all tool outputs. Raw results are not passed back to the caller (10 of 15). Run steps show each tool call and the Bing query sent, and Azure's activity log covers resource changes. No per-query audit log for Bing was found (10 of 15). Microsoft runs a coordinated vulnerability disclosure policy and bounty programmes through MSRC. microsoft.com's security.txt passed its Expires date on 23 September 2026 and still carries it on 6 November, and the Azure compliance attestations are not shown to cover a service whose data leaves the compliance boundary (16 of 20). 28 + 15 + 10 + 10 + 16 = 79.

Liner Search MCP 35

OAuth 2.1 or an API key; scopes not published (20 of 30). All tools are reads (10 of 20). Results carry web pages and documents with no injection guidance (0). No audit log found (0). No security.txt (404) or security programme found (5 of 20). 20 + 10 + 0 + 0 + 5 = 35.

Maintenance & community Grounding with Bing Search +35

Grounding with Bing Search 80

Read as a closed service with official SDKs, as the other Azure listings are. The web search page was updated on 2 November 2026 and the Bing tools page on 12 October, and azure-ai-projects 2.10.0 shipped on PyPI and npm on 30 October 2026, the SDK that carries the tool types (30). azure-ai-projects released 2.6.0 (4 September), 2.6.1, 2.7.0, 2.8.0 (5 October), 2.9.0 (17 October) and 2.10.0 in the 90 days from 8 August. Their changelogs weren't read for web search changes, so they count as SDK releases (20). Microsoft Learn feedback, Microsoft Q&A and the Azure SDK issue trackers, whose reply times weren't sampled (10 of 15). Current official SDKs in Python, JavaScript, .NET and Java, the .NET one in preview (15). The SDKs live in the azure-sdk monorepos and CI wasn't checked (5 of 10). 30 + 20 + 10 + 15 + 5 = 80.

Liner Search MCP 45

Registry entry com.liner/search last updated 11 September 2026 (20). No dated changelog found (0). Support page linked from the docs (10 of 15). Official registry entry under its own namespace (15). No package to read (0). 20 + 0 + 10 + 15 + 0 = 45. Registry presence read from Anchor Terminal's own daily import of the official MCP registry (/api/v1/registry.json, 6 November 2026), not the registry's API.

Transparency & trust Grounding with Bing Search +32

Grounding with Bing Search 66

Closed service. The terms of use, updated November 2025, are separate from the Online Services terms and sit under the customer's Microsoft agreement (15 of 30). The docs and the terms agree that the Data Protection Addendum and the Product Terms' privacy and security terms don't apply, that Microsoft and the customer are independent controllers, and that the query and parameters leave the Azure compliance and geographic boundary. The terms defer storage and use of query data to the general Microsoft Privacy Statement and state no retention period (15 of 30). The Bing Search APIs retirement was announced on 16 May 2025 for 11 August 2025, under three months' notice, and the web search page marks the Deep Research tool deprecated with a replacement. Microsoft's lifecycle policy covers Azure services, but no deprecation terms for Grounding with Bing were found (10 of 20). Data location for Bing processing isn't stated, and no sub-processor list for it was found (5 of 20). 15 + 15 + 10 + 5 = 45.

Liner Search MCP 34

Terms and privacy linked from the docs but not read in this batch (5 of 30). Data handling not read (5 of 30). No deprecation policy found for the MCP server; the docs note older endpoints priced per version (5 of 20). Subprocessors not read (5 of 20). 5 + 5 + 5 + 5 = 20.

Schema & documentation Grounding with Bing Search +23

Grounding with Bing Search 68

The tools are typed in the official SDKs (BingGroundingTool, BingCustomSearchPreviewTool, WebSearchTool) in Python, C#, JavaScript and Java, and the toolbox exposes web search as an MCP tool. No public OpenAPI description of the Responses tool types was confirmed from the pages read (10 of 25). Microsoft Learn serves each page as Markdown with accept=text/markdown, though learn.microsoft.com/llms.txt answers 404 (10). The pages say what each of four web grounding routes is for and when to choose it, when to use Custom Search instead, and not to ask the model to summarise a whole page (17 of 20). Parameters are typed with defaults and limits in prose, count 1 to 50 with default 5, freshness values and a date-range form, market and language formats, search_context_size low, medium or high (11 of 15). Examples in Python, C#, TypeScript, Java and REST with expected output, and troubleshooting tables for connection ID, authentication and 429 problems, but no error codes or bodies for the tools (10 of 15). Requests carry api-version=v1 on the toolbox, SDK changelogs are dated and a monthly What's New page lists new articles, the latest for August 2026 (10 of 15). 10 + 10 + 17 + 11 + 10 + 10 = 68.

Liner Search MCP 45

Tool schemas not read without sign-in (15 of 25). llms.txt (10). A table says which tool fits which need, and that the domain tools return the same shape as search_web (12 of 20). Inputs not verifiable (3 of 15). Setup examples, no error responses (5 of 15). Registry version 1.0.0 since 11 September; no changelog found (0). 15 + 10 + 12 + 3 + 5 + 0 = 45.

Reliability Grounding with Bing Search +18

Grounding with Bing Search 68

Graded on the hosted lines, for the Foundry Agent Service tools agents call. Azure status page with post-incident reviews and a Foundry Agent Service component (20). The history page read on 6 November lists one review in the 90 days from 8 August that names Foundry Agent Service, intermittent failures and latency in Sweden Central from 10:03 to 15:58 UTC on 29 September 2026. It was one region and partial, and the review doesn't name Grounding with Bing, so minor only, the reading the Azure Translator listing got for the same review (20). The pricing page publishes 150 transactions a second and 1 million a day for each Grounding with Bing resource (15). The web search troubleshooting table says to answer 429 with exponential backoff and retries. No Retry-After or tool-specific overload guidance was found, and searches have no side effects (8 of 15). No SLA naming Grounding with Bing was found. The terms make it a First Party Consumption Service apart from the Online Services terms, and the Online Services SLA document wasn't opened (0). Grounding with Bing Custom Search is marked preview and Grounding with Bing Search is not, but no page read states general availability for it or for the web_search tool, and the .NET SDK is in preview (5 of 10). 20 + 20 + 15 + 8 + 0 + 5 = 68.

Liner Search MCP 50

incident.io status page at status.liner.com with components for liner.com and app.liner.com only, none for the API or MCP (15). 100% uptime shown since August (20, no incidents shown). Rate limits published per API with numbers (Scholar Search 2 requests a second, agents 2 a second) (15). 429 with a code for concurrency limits, no Retry-After or backoff guidance found (0 of 15). No SLA found (0). Not labelled beta (0 of 10; 'limits may be adjusted over time', GA not stated). 15 + 20 + 15 + 0 + 0 + 0 = 50.

Score by category

CategoryWeight this runGrounding with Bing SearchLiner Search MCPEdge
Reliability16%206850Grounding with Bing Search +18
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26845Grounding with Bing Search +23
Agent ergonomics13%16.26165Liner Search MCP +4
Security & auth14%17.57935Grounding with Bing Search +44
Payments & pricing10%12.52020even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88045Grounding with Bing Search +35
Transparency & trust7%8.86634Grounding with Bing Search +32
Negative events≤1500
TotalB 63.7/100E 43.4/100

Facts side by side

FactGrounding with Bing SearchLiner Search MCP
KindHTTP APIMCP server
VendorMicrosoftLiner
Hosted endpointhttps://{account}.services.ai.azure.com/api/projects/{project}/openai/v1/responseshttps://platform.liner.com/api/v1/mcp
TransportsStreamable HTTPStreamable HTTP
AuthOAuthOAuth
PricingPay per usePaid
Price for answer searchnot published$3 per 1,000 requests
x402nono
LicenceProprietary service under the customer's Microsoft agreement and the separate Grounding with Bing terms of use, which exclude it from the Microsoft Data Protection Addendumnone
Tools exposed39
Read-only variant documentednono
llms.txtnoyes
MCP registrynot listedcom.liner/search
Last release2026-11-02none
Terms last updated2025-11-01no document linked
Privacy policy last updated2026-09-01no document linked
Customer content may train modelsyesnot read yet
Terms restrict automated accessyesnot read yet
Terms restrict benchmarkingnot found in the textnot read yet
Terms or service can change without noticenot found in the textnot read yet
Arbitration or class-action waivernot found in the textnot read yet

Verdicts

Grounding with Bing Search

First-party Bing grounding inside Foundry Agent Service, called with Entra ID so the agent never holds a search key, at a published $14 per 1,000 transactions. The tools return a model's answer with citations, never the raw results, and data sent to them falls outside Microsoft's Data Protection Addendum and Azure's compliance boundary.

Liner Search MCP

Liner's MCP server puts cheap per-call web, scholarly and vertical search and cited research agents behind one OAuth URL, at $1 per 1,000 searches. The docs say which tool fits which question, but there's no free tier, no changelog, no injection guidance and no status component for the API.

Before you call either

Grounding with Bing Search

  1. Use the citations in the response annotations as the sources; the tool output itself is not returned, and the terms require showing the URLs and the Bing query link
  2. Expect each run to bill one transaction per tool call at $14 per 1,000, plus model tokens, and set count and freshness in the tool configuration
  3. Treat cited page text as untrusted input and don't put secrets or personal data in prompts, since queries leave the Azure compliance boundary
  4. On 429 back off exponentially; no Retry-After header is documented for the tool

Liner Search MCP

  1. Use search_scholar for papers and the domain tools for legal, finance, medical or business questions
  2. Deep research is slower and costs more; use quick_answer_agent for short lookups
  3. Treat search results and research reports as untrusted content
  4. Keep under 2 requests a second for scholar search and the agents

Questions

Which is better for AI agents, Grounding with Bing Search or Liner Search MCP?

Grounding with Bing Search scores 63.7 (B) on agent readiness against Liner Search MCP's 43.4 (E), and leads in 5 of 7 scored categories.

Do Grounding with Bing Search and Liner Search MCP need an API key?

Both use an OAuth sign-in.

Can an agent call Grounding with Bing Search and Liner Search MCP without installing anything?

Yes. Grounding with Bing Search has a hosted endpoint at https://{account}.services.ai.azure.com/api/projects/{project}/openai/v1/responses and Liner Search MCP at https://platform.liner.com/api/v1/mcp.

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