Fitbit MCP Capabilities

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

Annotations already state readOnlyHint=true, destructiveHint=false, idempotentHint=true. The description adds meaningful context about the content of the explanation (data, privacy, workflow), which helps the agent understand the tool's output beyond safety annotations.

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 a single, front-loaded sentence covering all key aspects without redundant words, achieving maximum conciseness.

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 tool's simple meta-purpose, the existence of output schema, and annotations covering safety, the description provides sufficient context for an agent to understand what the tool returns and how it fits into the workflow.

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 only parameter response_format is self-explanatory from the schema enum, and the description does not mention it. With schema coverage at 0%, the description adds no value for this parameter, but since it's optional and well-defined, a baseline of 3 is appropriate.

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 uses a specific verb 'Explain' and lists clear topics (supported data, privacy boundaries, workflow, project links), clearly distinguishing it from data-retrieval sibling tools like fitbit_get_activity or fitbit_get_sleep_day.

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 implies this tool is for initial orientation, but does not provide explicit when-to-use or when-not-to-use guidance or mention alternative tools.

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