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

Annotations already establish read-only, idempotent, non-destructive behavior, and the description adds real context on top: the call is free, it must be made with the same connection or key that paid for it, and results include download_url plus filename for exports. The remaining gap is failure behavior for pending or failed jobs.

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 cost signal and then the two behavioral rules. Nothing is wasted, though the two "show it to the user" style instructions could be tightened into one.

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?

With no output schema, the description usefully sketches the return shape (download_url, filename, a token/credit summary line), which is exactly the right thing to cover. It is still incomplete about what happens when the job is incomplete, failed, or expired, which matters for a result-fetching tool.

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 the single job_id parameter has no in-schema description, so the description carries some of the burden by implying the job is the prepaid one tied to the calling key. It never says where job_id comes from or what its format is, so it does not fully compensate for the missing coverage.

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?

"Read the prepaid job" gives a specific verb and resource, and the note about downloaded files clarifies that this returns the job's actual output rather than just status. It never names get_job_status, so an agent must infer the boundary between the two siblings from their names alone.

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 credential rule ("using the connection or key that paid for it") is a genuine usage precondition, and the presentation instructions tell the agent how to hand results back to the user. It never says when to use this versus get_job_status, nor what to do if the job is not yet finished.

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