query_metric

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

With no annotations, the description effectively discloses key behaviors: windows <=30 days return raw samples, longer windows return daily aggregates, and raw samples beyond 30 days are summarized. Adds value beyond schema.

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?

Concise (4 lines) with clear structure: purpose statement, examples, then behavioral rules. No fluff, but could be more structured with bullet points.

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?

Covers the main behavioral aspect (window vs aggregation) but partially explains parameters (missing limit). Given it has an output schema, return values need not be detailed, but the tool is fairly simple and the description is sufficient but not rich.

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 description must compensate. It explains 'metric_type' with examples and implies 'days' controls window length, but does not explain 'limit'. Some added meaning, but not fully comprehensive.

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?

Clearly states the tool retrieves time-series for any HealthKit metric type with examples, but does not explicitly differentiate itself from sibling tools like compare_periods or get_daily_snapshot.

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 versus alternatives (e.g., get_daily_snapshot for single-day aggregation, compare_periods for comparisons). The description only provides behavioral details about window sizes.

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