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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses pricing per endpoint and global coverage, which is helpful, but it does not mention whether the API is read-only, requires authentication, has rate limits, or what the response format or error behavior is. This is a significant gap for an external API.

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 fairly concise and well-structured: a lead sentence followed by a scannable bulleted list of endpoints with prices and one-line explanations. It efficiently covers the tool's scope, though the first line is truncated ('plateau-breaki') and the list is somewhat long.

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?

This is a complex tool with 22 parameters, 10 endpoints, and no output schema. The description explains what each endpoint offers but omits essential context such as return payload structure, examples of how to invoke endpoints, required parameters per endpoint, and any operational limitations. This leaves the agent under-informed for a tool of this complexity.

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 input schema provides descriptions for all 22 parameters (100% coverage), so the baseline is 3. The description adds no parameter-level details and only hints at parameter relevance through endpoint names (e.g., race_date for race), but it does not enhance understanding 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 clearly identifies FitPulse as a 'Global fitness intelligence API' and enumerates ten specific endpoints (workout, nutrition, supplement, recover, sleep, race, etc.), which makes its purpose explicit and distinct from sibling tools in the fitness domain. The scope and resource are unambiguous.

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 endpoint list provides implicit intra-tool guidance, e.g., 'nutrition: Macro and nutrition targets' tells the agent which action to use for nutrition queries. However, it does not explicitly state when to choose FitPulse over other 'pulse' tools, nor does it offer alternatives or exclusions, so the guidance is implied rather than fully explicit.

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