fitbit_get_exercises

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

With no annotations, the description discloses default cache behavior, live fetch option, return fields, and notes HR data unreliability for cycling. Adds valuable behavioral context.

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?

Well-structured with a brief summary, bullet-like parameter list, and a note. Slightly longer but every sentence adds value; front-loaded with main purpose.

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?

Despite no annotations, the description covers parameters, return values, cache behavior, and a reliability note, making it complete for a data retrieval tool with output schema.

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?

Compensates fully for 0% schema coverage by detailing each parameter with format, default, and filtering behavior (e.g., start_date accepts '30d', exercise_type does case-insensitive substring match).

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 it retrieves exercise log entries (individual tracked activities), distinguishing it from sibling tools like fitbit_get_heart_rate or fitbit_get_sleep.

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?

Provides explicit guidance on using cache vs live, and instructs to run fitbit_sync first. Does not explicitly mention when not to use, but gives clear context for usage.

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