get_workout_fit

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

With no annotations, the description carries full burden. It discloses that the tool is read-only and describes output size implications for full=true, warning of >100 KB responses. It also details the default summary fields and sampling strategy (first/middle/last 5 records), providing meaningful behavioral context beyond the input 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 concise at 4 sentences, front-loaded with the core purpose, and each sentence earns its place. It uses bullet-like structure in the summary explanation without being verbose. No redundancy with schema or annotations.

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 no output schema, the description adequately specifies the return format for both modes, including fields for compact summary and size warning. For a tool with only 2 parameters and clear behavior, the description covers all necessary aspects for an agent to select and invoke 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?

Input schema coverage is 100%, but the description adds significant value: it explains that workoutKey is an opaque string not guessable and must be discovered via list_workouts. For the full parameter, it clarifies the default behavior and impacts on response size, surpassing the schema's basic type and default value description.

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 the tool downloads a FIT file and returns parsed JSON, distinguishing between default compact summary and full=true raw data. It is specific about the verb (downloads/returns) and resource (workout FIT binary), and the mention of returning parsed JSON differentiates it from siblings like get_workout or get_workout_samples.

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 provides explicit guidance on when to use default vs full=true, noting that full=true is only for raw record-level data and defaults are sufficient for analysis. It also implies that workoutKey must be obtained via list_workouts first, though it does not explicitly state when to use this tool over sibling tools. The context of sibling tools suggests alternatives, but no direct exclusions are given.

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