cancel_queue_item

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

With no annotations, the description carries the full burden and does so: it labels the operation destructive, states the concrete consequence ('the request to build is discarded'), and enumerates the three required permissions (MCP_ALLOW_BUILD_WRITE, MCP_ALLOW_DESTRUCTIVE, MCP_ALLOW_BUILD_STOP). This is exactly the behavioral context an agent needs before calling a mutation tool.

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

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

Front-loads purpose, then destruction, then parameter source, then the alternative tool, then auth requirements. Every sentence adds distinct information with no repetition of the schema.

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

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

For a single-argument cancel tool with no output schema, the definition covers purpose, consequence, argument provenance, sibling routing, and permission prerequisites. Nothing an agent needs to invoke it correctly is missing.

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

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

Schema coverage is 0% and there is a single parameter, so the description must compensate. It does well by naming the source of item_id (get_queue) and explicitly disambiguating it from a build number, but it does not describe the integer format or error behavior for stale/invalid ids beyond what the schema implies.

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

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

States a specific verb (Remove/cancel) and resource (queued item) with precise scope ('before it starts'), and explicitly contrasts with the sibling stop_build for running builds. An agent can distinguish it from get_queue_item and stop_build without opening any schema.

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

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

Names the alternative (stop_build) and the exact condition that selects it (build already running), defining when NOT to use this tool. It also tells the agent where the required argument comes from (get_queue), leaving nothing to inference.

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