set_heart_rate_zones

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

With annotations only providing basic hints (readOnly=false, destructive=false), the description adds critical behavior: it does a GET, overlays fields, PUTs, and reads back; it notes that a sport without a profile starts from DEFAULT; that setting restingHeartRate turns off auto-update; that Garmin does not recompute floors; and that floors must be strictly ascending or it 400s. This is rich and non-obvious.

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 dense but front-loaded with the main operation, then details constraints. It is appropriately sized for a complex mutation, though the truncated ending ("ascendi…") slightly hurts clarity. Every sentence earns its place.

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 complexity (READ-MODIFY-WRITE, nested object, no output schema), the description covers everything an agent needs: the sequence, defaults, side effects, error conditions, and floor requirements. It is complete for correct invocation.

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?

Even though the schema has 0% description coverage (only type info), the description compensates extensively: it explains the overlay object, lists each field and its meaning (sport defaults to DEFAULT, zoneFloors need 5 bpm values, restingHeartRate side effect, trainingMethod enum values, etc.). This adds substantial meaning beyond the schema.

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+resource: it modifies heart rate zones for a profile, using a precise READ-MODIFY-WRITE pattern with exact HTTP endpoints. It distinguishes itself from sibling tools like get_heart_rate_zones and delete_heart_rate_zones by describing the multi-step write operation.

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?

It clearly implies usage: you call it to set/update heart rate zones, with a specific sport or DEFAULT. However, it does not explicitly say when to call it versus alternatives or preconditions (e.g., need a profile), though the READ-MODIFY-WRITE pattern implicitly suggests the operation is idempotent and requires reading first.

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