list_metrics

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

With no annotations provided, the description carries full burden but only states it's for 'discovering metrics' without disclosing behavioral traits like whether this is a read-only operation, potential rate limits, authentication requirements, or what the response format looks like. It mentions pagination indirectly through the cursor parameter but doesn't explain the pagination behavior.

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 sentences with zero waste - the first states the purpose, the second provides usage guidance. Every word earns its place, and the most important information (what the tool does) is front-loaded.

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 4 parameters, 100% schema coverage, but no annotations and no output schema, the description is adequate but has gaps. It explains the purpose and relationship to get_metrics, but doesn't address behavioral aspects like safety, performance, or response format that would be helpful given the lack of annotations.

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 fully documents all 4 parameters. The description adds no additional parameter semantics beyond what's in the schema descriptions. The baseline of 3 is appropriate when the schema does all the work.

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 states the tool's purpose: 'List all available metrics from Datadog' with the specific verb 'List' and resource 'metrics'. It distinguishes from sibling 'get_metrics' by noting it's for discovery before querying, but doesn't explicitly differentiate from other list_* tools like list_monitors or list_slos.

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 provides clear context: 'Useful for discovering metrics before querying them with get_metrics.' This gives explicit guidance on when to use this tool versus its sibling 'get_metrics', but doesn't mention when not to use it or alternatives among other list_* tools.

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