get_heart_rate_history

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

With no annotations, the description fully covers behavior: returns all samples in past N hours, sorted oldest-first, from Apple Watch and HealthKit sources. It also describes the return format (JSON with bpm/timestamp/source/device).

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 (5 sentences) with a clear front-loaded purpose, followed by parameter details and return format. Every sentence contributes meaning without redundancy.

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 simple one-parameter tool, the description is complete: it explains the function, input, output, data sources, and constraints. The existence of an output schema is acknowledged but not required for completeness here.

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 parameter 'hours' is explained with its meaning, default, and maximum value, adding significant value beyond the schema which only provides type and default. This compensates for the 0% schema description coverage.

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 'retrieve' and resource 'heart rate history' from macOS HealthKit. It specifies the time window (past N hours) and sorting, distinguishing it from siblings like get_heart_rate (single point) and stream_heart_rate (real-time).

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 explains the purpose and parameter constraints (default 24, max 168 hours), implicitly guiding use for historical data. However, it lacks explicit when-to-use vs alternatives or exclusions.

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