Icu Get Fitness Chart

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations by explaining that the series includes past history plus future projections from planned calendar workouts, which clarifies the data source and scope. It does not cover pagination or auth requirements, but those are minor given the rich annotations and output schema.

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 front-loaded with the core purpose and return values, followed by compact 'Use for' and 'NOT for' routing lines. Every sentence earns its place: there is no filler, and the exclusions are directly tied to sibling alternatives.

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 output schema exists, the description need not explain return values, and the annotations cover safety and idempotency. The description is complete for this tool: it explains purpose, data source, when to use it, and when to use a sibling instead. Nothing an agent needs in order to call it correctly is missing.

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?

Schema description coverage is 100%, so all three parameters (days_back, days_ahead, athlete_id) are already fully documented in the schema. The description implies that days_back covers past history and days_ahead covers projections, but it does not add syntax, units, or format details beyond what the schema provides. Baseline 3 is appropriate when the schema does the heavy lifting.

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?

States a specific verb (Fetch), resource (Performance Management Chart time-series), and the exact metrics returned (daily CTL, ATL, TSB). It explicitly distinguishes itself from sibling tools like icu_get_fitness_summary and icu_get_wellness_data, so an agent can select it without opening the schema.

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 positive use cases ('show my fitness chart', 'CTL trend last 90 days', projected TSB) and explicit negative cases with named alternatives for training recommendations, HRV/sleep trends, and single-day wellness records. This is exactly the when/when-not/alternatives guidance that enables correct tool routing.

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