tp_get_fitness

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

Without annotations, the description carries full burden. It discloses that the API fetches extra history for exponential decay calculation, which is a notable hidden behavior. It also describes return values (daily load data, current status).

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 structured with a main purpose sentence, an Args section, and a Returns note. It is concise (7 sentences) with no fluff, front-loading the core function.

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 3 optional parameters, no enums, and an output schema, the description fully covers parameter interactions, return type, and the extra fetch behavior. It provides sufficient context for an agent to use the tool correctly.

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?

With 0% schema description coverage, the description adds critical meaning: explains days default 90, that start_date overrides days, and the expected date format (YYYY-MM-DD). This goes beyond the schema's minimal info.

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 CTL, ATL, and TSB performance data, specifying the resource (fitness data) and action (get). It distinguishes from siblings by mentioning daily training load with computed values and extra history fetch.

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 explains parameter behavior (days vs start_date) but does not provide explicit guidance on when to use this tool over alternatives like tp_fitness_trend or tp_training_load_summary.

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