get_test_run_statistics

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

The annotations already state readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds only that filtering is optional; it does not clarify what the statistics contain, whether the filter is applied to result fields, or how large a response may be.

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 definition is a single efficient sentence with the core action front-loaded. It is appropriately brief, though "statistics" remains broad enough that a little more specificity might have earned a 5.

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 two-parameter read-only tool with full schema coverage, this is mostly adequate. However, the lack of output schema means the description should ideally say more about what statistics are returned, and it should distinguish this endpoint from get_test_results_statistics.

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 100%, so the schema already explains that id is a test run UUID and filter is an optional narrowing body. The description reinforces those meanings but adds no format, allowed filter keys, or syntax beyond what the schema provides, making 3 the correct baseline.

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 gives a clear verb and resource: get statistics for a specific test run, optionally filtered. It is understandable in isolation, but it does not distinguish this tool from the nearby sibling get_test_results_statistics, leaving an agent to guess which statistics endpoint applies.

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 "optionally filtered" implies that the filter parameter can be used to narrow results, but there is no explicit when-to-use guidance, no when-not-to-use guidance, and no routing to the similarly named get_test_results_statistics alternative.

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