YC GraphQL MCP

by arthurcolle

Overview Schema Source Related Servers Discussions Admin

TypeScript

Local

yc_run_operation

Read-onlyIdempotent

Execute a locally registered GraphQL query with variables; mutations require preview and commit before running.

Instructions

Execute a locally registered query with variables. Registered mutations still require preview and commit.

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": {
      "operationName": "<operationName>"
    },
    "name": "yc_run_operation"
  }
}

Input Schema

Name	Required	Description	Default
`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 declare readOnlyHint and idempotentHint, so the bar is lower, but the description adds real context: the operation must be locally registered first, and mutations cannot be executed here without preview and commit. It does not discuss failure modes or what happens when the operation name is unregistered.

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?

Two short sentences, front-loaded with the action and followed by the single most important constraint. Nothing is wasted.

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?

For a two-parameter tool with an output schema covering return values and annotations covering safety, the description supplies the key prerequisite (local registration) and the mutation restriction. The only real gap is variable payload semantics.

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 description coverage is 0%, so the description has to compensate. It clarifies that operationName refers to a locally registered operation and that variables are passed to it, but it gives no detail on the variables object shape or the name pattern/length constraints encoded in the schema.

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 a locally registered query with variables. The second sentence carves mutations out of scope, though it leaves slight ambiguity about whether the tool can also run registered mutations via a different path.

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?

It implies the mutation path needs preview plus commit, which routes the agent toward the prepare/commit siblings, but it never names an alternative for plain queries (e.g. yc_query) or says when to prefer those tools.

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