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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, and the description reinforces this with 'changes nothing.' It adds valuable context beyond annotations: links expire after 15 minutes, files are kept 30 days, and an unlocked job returns an error with state and cost. It does not contradict annotations.

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?

The description is dense but every sentence earns its place: purpose, usage timing, side-effect-free guarantee, return shape, link lifetime, file retention, and error behavior. It is front-loaded with the core purpose and then layers necessary operational 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 single-parameter read-only tool with no output schema, the description covers the return shape, link expiry, file retention, error behavior, and how to handle the links. An agent has everything needed to call it correctly and interpret the result.

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 schema already documents job_id as a UUID of an unlocked job. The description adds the precondition that unlock_job must have succeeded, which is meaningful semantic context beyond the schema's wording.

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 states a specific verb ('get signed download links'), a resource ('finished files of a job'), and a precondition ('once unlock_job has succeeded'). It clearly distinguishes from siblings like unlock_job and get_job by focusing on the download-link step.

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?

Explicitly says to use it as the last step of the flow and again when links expire, and tells the agent to call unlock_job first if the job is not unlocked. It also gives practical guidance on fetching files with curl versus giving links to the customer.

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