Cancel a background job

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

Goes well beyond the annotations: it discloses what is destroyed (child process), what is preserved (build artifacts already written), what happens if you don't call it (abandoned job keeps running and holding the project directory), and that the action is not reversible. This is consistent with destructiveHint=true and adds real operational context.

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?

Three short sentences, front-loaded with the action and mechanism, followed by the usage rule and the consequence caveat. No filler or repetition.

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 one-parameter mutation tool with annotations covering safety profile and no output schema, the description supplies everything needed: what it does, why to prefer it, and the side-effect boundary. Nothing material 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?

Only one parameter (jobId) and schema description coverage is 100%, so the schema already documents it fully. The description adds no format, source, or id-acquisition guidance beyond the schema, which is the baseline-3 case.

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 and resource — 'Terminate a running background job by killing its child process' — with the mechanism included. An agent can immediately distinguish this from job_status or any of the project/file editing siblings.

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?

Gives explicit when-to-use guidance ('Use this rather than abandoning a job') and explains why the alternative is bad. It does not name a sibling tool (e.g. job_status) as the counterpoint, so routing is slightly inferential, but the condition that selects this tool is unambiguous.

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