get_incident_metrics_by_service

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

Annotations already signal read-only, idempotent, non-destructive behavior. The description adds context about aggregation via PagerDuty Analytics, but doesn't reveal additional behavioral traits beyond what annotations provide. It is consistent and adds marginal value.

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 description is concise, with key information front-loaded. It uses a clear structure: purpose, metrics, usage guidance, then parameter and return details. No redundant sentences.

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?

All 8 parameters are described, required parameters highlighted, output model referenced (with output schema present), and alternative tools mentioned. No gaps for an 8-parameter tool with output schema.

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?

The input schema has 0% description coverage, but the text fully describes each parameter with examples and semantics (e.g., 'created_at_start: ISO8601 DateTime. Incidents created before this are omitted'). This adds substantial meaning beyond the schema alone.

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 verb ('Get'), the resource ('incident metrics per service'), and the specific metrics (MTTA, MTTR, etc.). It also distinguishes this tool from list_incidents by highlighting pre-aggregation, making its purpose unambiguous.

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?

Explicit guidance is given: 'Use this instead of list_incidents when you need service health metrics — data is pre-aggregated.' This clarifies the appropriate context. A minor improvement would be to explicitly state when not to use it (e.g., for raw incident data), but the guidance is already effective.

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