Check a job

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds valuable behavioral context: it returns only new events when a cursor is passed, and it returns the final answer once the run completes. This goes beyond the annotations by explaining the incremental polling behavior and completion semantics.

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 sentences, each earning its place: the first states the core purpose, the second explains the cursor behavior, the third states the completion behavior. No fluff, no repetition of schema details.

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 polling tool with readOnly and idempotent annotations, the description covers the essential behavior: progress, result, incremental events, and final answer. It doesn't describe error cases or what happens on timeout, but the waitSeconds parameter and the polling pattern make those less critical. The lack of an output schema means the description could have said more about the return shape, but the core usage is complete.

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 description coverage is only 33% (only cursor has a description). The description explains the cursor parameter's purpose ('Pass the cursor from the previous call to receive only new events'), which adds meaning. However, jobId and waitSeconds are not described in the schema or the description, so the agent must infer their semantics from names and constraints. The description partially compensates but doesn't fully cover the gap.

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?

The description clearly states the tool polls a job for progress and result, with a specific verb ('Poll') and resource ('a job'). It distinguishes itself from siblings like claude_run (which presumably starts a job) and claude_cancel (which cancels one). The title 'Check a job' reinforces the purpose.

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?

The description explains the polling mechanism and how to use the cursor for incremental updates, which implies the usage context (polling after starting a job). It doesn't explicitly name alternatives or state when not to use it, but the sibling list and the polling semantics make the usage clear.

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