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

The description adds the ordering behavior—'oldest first; the last entry is the latest run'—which is not available in the annotations or schema. The annotations already cover read-only and non-destructive behavior, so this extra ordering detail is meaningful behavioral context beyond what is structured.

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 a single sentence with the core action and ordering detail front-loaded. There is no filler, and every clause adds meaning.

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?

The tool is low-complexity: one required param, no enums, and an output schema is present. Annotations cover safety, and the description covers the key behavioral guarantee (ordering). No critical detail appears missing for an agent to call this tool correctly.

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?

The input schema has zero description coverage for job_id, so the description carries the burden. The sentence maps job_id to 'a job' and clarifies the output ordering, but it does not add details about the ID's format, domain, or required existence. For a single, self-explanatory parameter, this is adequate but not rich.

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 'List runs for a job'—a specific verb plus resource with a scope qualifier. It clearly distinguishes this tool from siblings like list_formats, check_run, and wait_for_run by naming the resource and operation.

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 phrase 'for a job' gives a clear condition for when to use the tool, but it does not explicitly mention alternatives or state when not to use sibling tools. The context signal of a single job_id makes usage obvious, but the description leaves the choice of, say, check_run over list_runs to the agent's inference.

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