get_metrics

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

The description reveals that the tool returns min/mean/p95/latest and SLO breach status, adding valuable context beyond the readOnlyHint and openWorldHint annotations. It also conveys the tool's judgment-focused behavior ('so you get the judgement and not just the numbers'), which helps the agent understand the tool's output character. No contradictions with annotations.

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 two sentences, front-loaded with the core purpose. The second sentence adds concise and useful output details without redundancy. Every sentence earns its place, making it highly efficient.

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?

Given the tool has 3 parameters and an output schema, the description covers the essential purpose and return value highlights. It doesn't mention edge cases, error scenarios, or relationships to sibling tools, but for a read-only metric summarizer, it is largely complete. Slight gap in usage context prevents a 5.

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 0%, so the description must compensate. It maps the parameters conceptually: 'one metric' → metric, 'one service' → service, 'over a window' → since_minutes. However, it doesn't elaborate on allowed values or the meaning of the metric enum, leaving the schema names to carry the load. This is adequate but not fully compensating for the lack of parameter descriptions.

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 action: 'Summarise one metric for one service over a window.' It distinguishes itself from sibling tools by focusing on metrics and SLO status, but it doesn't explicitly name alternatives like query_logs or correlate_deploy_with_errors, so it misses the top score.

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?

Usage is implied through the purpose statement, but the description does not provide explicit guidance on when to choose this tool over its siblings, nor does it mention any exclusions or prerequisites. It merely describes what the tool does, leaving the when-to-use context to the agent.

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