compare_runs

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

No annotations exist, so the description carries the full behavioral burden. It usefully enumerates the comparison dimensions (latency, cost, tokens, tools, failures) but says nothing about cardinality limits, whether runs must be compatible, or any auth/rate constraints; with an output schema present, the return shape is covered elsewhere.

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 front-loaded sentence with zero filler; the resource and the compared metrics come before anything else.

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 one-parameter read tool with an output schema, the description covers what the tool does but leaves usage conditions and constraints to inference. Adequate, not complete.

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 0% and the single parameter is only titled 'Trace Ids'. The description's phrase 'trace-id prefixes' is the one piece of semantic information available, and it materially changes how the agent should populate the array (prefixes rather than exact ids).

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?

States a specific verb ('compare') and resource ('trace-id prefixes') plus the exact metrics compared, so the agent knows what it produces. It does not differentiate itself from conceptually adjacent siblings like run_summary or tool_stats, which keeps it below a 5.

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?

There is no explicit when-to-use, when-not-to-use, or alternative named. 'Selected' hints that the caller supplies the set, but nothing tells the agent when comparison is preferable to run_summary or list_runs.

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