runs

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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds behavioral context beyond annotations by specifying ordering ('newest first') and the exact fields returned, which helps the agent know what to expect. It does not contradict the 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?

Two compact sentences contain the essential information: what the tool returns and when to use it. There is no filler or repetition of schema/annotation data. The field list is front-loaded, and the usage guidance is immediately actionable.

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 simple read-only list tool, the description is nearly complete: it lists the output fields, states ordering, and explains the tool's purpose in relation to the other tools. There is no output schema, but the description supplies the key return information. Minor ambiguity remains around the meaning of 'kind' and 'verdict' values, but it does not block correct invocation.

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 only parameter, repo, is fully described in the schema with its default behavior. Schema description coverage is 100%, so the description does not need to add parameter semantics. The tool description adds no extra parameter detail, but the baseline of 3 applies because the schema already carries the full burden.

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 identifies the tool as a run-history listing tool and enumerates the returned fields: id, kind, verdict, commit, and lane set. It does not use an explicit verb like 'list', but the resource and scope are unmistakable. It also gives a purpose ('date the store', 'check which commit the other tools answer from') that differentiates it from the sibling tools.

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?

'Use it to date the store or to check which commit the other tools answer from' provides explicit, concrete use cases. It does not mention alternatives or when not to use it, but the context is clear enough for an agent to select it appropriately among siblings.

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