get_body_composition

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

Since no annotations were provided, the description carries the full behavioral burden. It discloses essential behavioral traits: this is a 'Personal API only' function and that secondary metrics (fat/muscle) are conditional upon the device reporting them, which is vital for agent expectation setting.

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 reasonably concise but contains some commentary ('unofficial flow') that isn't strictly necessary for execution. It front-loads the core utility (Weight from Garmin) but could be tighter overall.

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?

The definition is quite complete given the simple parameter count and the specialized nature of the data. It tells the agent exactly what metrics to expect and the necessary operational context (Garmin/Personal API), which is the most important information.

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 100% schema description coverage, the baseline score for parameter semantics is 3. The description provides no additional semantic meaning regarding how the 'days' lookback window should be interpreted or constrained beyond what the schema already provides.

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 is highly specific, clearly stating the function (retrieving weight/body fat/muscle) and the source (Garmin Connect). This immediately differentiates it from sibling tools that provide general activity summaries or health stats.

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 strong motivational context, stating that weight is critical for fitness decisions. However, it does not explicitly define when *not* to use it, nor does it offer clear comparisons to other similar health tools like get_health_summary.

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