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

Annotations already declare readOnly/idempotent, and the description adds substantial context beyond them: full status enumeration, expiry semantics (7 days after the run ends), cost (Free), and a specific error case (run_not_found for unknown, foreign, or expired runs). This is unusually rich behavioral disclosure.

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?

It is a dense single block, but front-loaded with the core action and mode split before output details, cost, and errors. Every sentence carries information; minor cost is that the output-field enumeration is a long run-on list that could be structured, but no sentence is wasted.

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 carries the full return-value burden and does so thoroughly (id, kind, status, error, progress, lookups, expires_at, results, next_offset). Combined with 100% parameter coverage, an agent has everything needed to call and interpret it.

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%, so baseline is 3; the description adds meaning by linking the offset parameter to the next_offset output field and explaining pagination behavior, and clarifies the run_id format ('run_ followed by 24 hex characters') and omit-to-list behavior.

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 opens with a specific verb and resource ('Get the status, progress and lookups charged for a run') and immediately distinguishes two modes: with run_id it fetches one run's status/results, without it lists recent runs. It explicitly ties itself to the sibling start_run, so an agent can route between them.

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?

It explains when results are available ('while it is still running'), how to page (pass next_offset as offset), and points to the REST DELETE endpoint for cancellation rather than implying this tool cancels. It lacks explicit when-not-to-use guidance relative to other siblings like get_usage, but provides clear operational context.

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