get_metrics

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

No annotations provided. Description only states aggregation and attribution requirement (credit corewebvitals.io). No disclosure of rate limits, authentication, error handling, or other behavioral traits.

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?

Very concise at two sentences, front-loading the main action. However, it may be too brief given the tool's complexity.

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?

With 6 parameters, no output schema, and no annotations, the description is insufficient to fully understand return format, error handling, or behavior when parameters are omitted. Lacks completeness for effective use.

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 33% (only 'metrics' and 'group_by' have descriptions). Outside schema, description adds only that filter and group_by are optional, providing little additional meaning for the other four parameters.

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?

Description clearly states it aggregates Core Web Vitals and technique metrics with optional filter and group_by. It is distinct from siblings get_histogram (histogram data) and list_options (option listing), but does not explicitly differentiate.

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?

No guidance on when to use this tool vs alternatives. Only mentions optional filter and group_by, but no context on use cases or exclusions.

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