run_test

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

The readOnlyHint annotation already signals a non-mutating operation, so the description does not need to repeat that. It adds value by clarifying the optional-model behavior (all tests when omitted), but it does not disclose whether test output, results, or artifacts are returned or recorded. This is adequate but not rich.

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?

A single sentence with no filler, and the optional behavior is front-loaded. Every phrase contributes meaning, making it an appropriately concise definition.

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 tool with one optional parameter and no output schema, the description covers the essential calling decision: what runs when model_name is provided versus omitted. It is complete enough for an agent to invoke correctly, though return-value expectations are not described.

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 description coverage is 0%, so the description must compensate. It does so by explaining the only parameter's behavior: providing model_name targets one model, omitting it runs all tests. This adds meaning beyond the raw 'default: null' in the schema, though it could specify the expected format of model_name.

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 action ('Run unit tests') and a specific resource ('for a model'), with the scope clarified by the parenthetical 'or all tests if omitted.' It is clear and actionable, though it does not explicitly differentiate this from the sibling 'run' tool beyond naming the test domain.

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 description implies the tool is for running unit tests, but gives no explicit guidance on when to choose it over siblings like 'run' or 'run_audit.' There is no mention of prerequisites, intended contexts, or exclusions, leaving the selection decision to inference.

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