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Preview a named operation locally

preview_operation

Read-onlyIdempotent

Validate a Buffer GraphQL operation and its arguments, returning the document and variables without credentials or sending a request.

Instructions

Validate a current named input and upstream field selection, then return document and variables without credentials or a request. Does not validate permissions, assets or platform rules remotely. Operation names use native GraphQL camelCase.

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": {
      "operation": "<operation>",
      "arguments": "<arguments>"
    },
    "name": "preview_operation"
  }
}

Input Schema

Name	Required	Description	Default
`arguments`	Yes	Arguments for that named tool. Provide all required native input, including organizationId; profile defaults are not read.
`operation`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv2.0.0Oct 3, 2026

TDQS

A3.7/5.0

Behavior4/5

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description still adds real value by disclosing that it makes no request, needs no credentials, and does NOT validate permissions/assets/platform rules remotely — behavior an agent could not infer from the annotations.

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

Conciseness4/5

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

Three tight sentences with the core purpose front-loaded first, followed by the limitation and the naming convention. No filler, though the closing sentence on camelCase could be integrated more smoothly.

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?

With no output schema, the description compensates by naming the return values (document and variables) and enumerating the offloaded limitations. For a two-parameter, no-request validation tool this is nearly complete; only the format/shape of the returned document and variables is left underspecified.

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 50%, so the schema carries half the burden. The description adds meaningful guidance beyond it — 'Operation names use native GraphQL camelCase' clarifies the operation enum, and 'including organizationId; profile defaults are not read' is already inside the arguments schema description. Baseline 3 is appropriate; it does not add syntax beyond the enum hint.

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?

The description gives a specific verb (validate) and resource (named operation input plus upstream field selection) and states the concrete output: document and variables without a request. It implicitly distinguishes itself from execution tools like graphql_query/graphql_mutation by emphasizing 'without credentials or a request', but never names a sibling explicitly, so it falls short of a 5.

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?

The phrase 'without credentials or a request' implies this is a pre-flight/dry-run check, and 'Does not validate permissions, assets or platform rules remotely' sets a boundary. However, it never states when to use this instead of graphql_query/graphql_mutation or get_operation_schema, so usage is only implied rather than spelled out.

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