subagent_cancel

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

With no annotations, the description carries the full burden but only discloses one behavioral trait: the cascading termination of every process the job started, which is genuinely useful and non-obvious. It omits permissions required, what occurs if the job already finished, reversibility, and return behavior.

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?

One sentence, front-loaded with the action and extended only with the scope detail that matters. Nothing is wasted or buried.

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?

A destructive single-param tool with no annotations and no output schema. The cascade behavior is covered, but the description should say what a successful cancellation returns and what happens on an already-completed or unknown job_id.

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 100% and the single parameter is fully documented in the schema ('Job ID returned by subagent_start'). The description adds no syntax, format, or sourcing detail beyond the schema, so the baseline of 3 applies.

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?

Specific verb ('Stop') plus resource ('a running job') and it clarifies scope by noting it also terminates child processes the job started. An agent can distinguish it from siblings like subagent_status or subagent_wait, though it never names an alternative explicitly.

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?

No guidance on when to cancel versus letting a job finish, checking subagent_status first, or whether cancellation is safe/needed after subagent_result. The description assumes the agent already knows it wants to cancel.

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