get_heart_rates

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

With no annotations, the description carries the burden of behavioral disclosure. It adds useful context about payload size and granularity: 'detailed 2-minute interval data (~25KB)'. It does not cover timezone/units or error behavior, but the output schema can cover return details.

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 short, front-loaded with purpose, and every sentence provides value: full scope, data granularity/size, sibling alternative, and parameter format. No filler.

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?

For a one-parameter read tool with an output schema, the description is complete. It explains what data is returned, the volume, the parameter format, and when to choose the summary sibling instead.

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%, but the description fully compensates for the single parameter: 'date: Date in YYYY-MM-DD format'. This provides the exact format the schema lacks.

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 states a specific verb and resource: 'Get full heart rate time-series data'. It strongly distinguishes itself from the sibling get_heart_rates_summary by emphasizing 'full' and 'detailed 2-minute interval data'.

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 explicitly directs the agent to the alternative: 'For a compact summary, use get_heart_rates_summary()'. This provides clear when-to-use and when-not-to-use guidance relative to the key sibling tool.

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