YC GraphQL MCP

Overview Schema Source Related Servers Discussions Admin

yc_query

Read-onlyIdempotent

Run exactly one explicitly named GraphQL query with variables to read YC application and founder-profile data; mutations and subscriptions are rejected.

Instructions

Execute exactly one explicitly named GraphQL query with variables. Mutations and subscriptions are rejected by the AST parser. No automatic retry.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "query": "<query>",
      "operationName": "<operationName>"
    },
    "name": "yc_query"
  }
}

Input Schema

Name	Required	Description	Default
`query`	Yes
`variables`	No
`operationName`	Yes

Output Schema

Name	Required	Description	Default
`ok`	Yes
`data`	No
`error`	No
`untrustedContent`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv2.1.0Nov 12, 2026

TDQS

A3.8/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover safety (readOnly, idempotent, non-destructive, openWorld), and the description adds real behavioral context beyond them: a single operation per call, AST-level rejection of mutations/subscriptions, and no automatic retry. It omits auth requirements, rate limits, and error surface, which keeps it below a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, each carrying a distinct constraint, with the core action front-loaded. No filler or restatement of the title.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists and annotations carry the safety profile, so the description only needs to cover execution contract, which it largely does (single query, named operation, no retry). Missing failure/paging behavior and the operationName-to-document relationship keep it from a 5.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, so the description carries the burden, and it only partially does: 'with variables' and 'explicitly named' gesture at the variables and operationName parameters without explaining the variable-object shape or that operationName must match an operation in the document. It adds some meaning but leaves the two required parameters under-explained.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Execute exactly one ... GraphQL query') plus a scope constraint (exactly one, explicitly named, with variables). It implicitly separates itself from mutation siblings by declaring that mutations and subscriptions are rejected, though it never names an alternative directly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied rather than spelled out: the AST rejection of mutations/subscriptions tells an agent this is the read path and that write operations belong elsewhere (e.g. the mutation siblings). There is no explicit 'use this when / use X instead' routing statement.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.