garmin_health_snapshot

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

No annotations are provided, so the description bears full responsibility for behavioral disclosure. It states what is measured but doesn't mention authentication needs, rate limits, data latency, or any operational constraints. For a read-only tool, the description could at least confirm it's a read operation and note that results depend on the user having performed recent snapshots.

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?

Two concise sentences that front-load the core purpose. No wasted words; every sentence adds useful information about what the tool returns and where the data comes from.

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 tool has no parameters, no annotations, and an output schema exists (so return format need not be described), the description provides sufficient context for an agent to understand what the tool delivers. It could be improved by mentioning when to prefer it over individual metric tools, but overall it's complete for a zero-parameter data retrieval tool.

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 tool takes zero parameters, so parameter semantics are not a concern. The description appropriately focuses on output content instead. Baseline 4 applies for zero-parameter tools.

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 returns on-demand Health Snapshot readings (2-minute wrist measurements) capturing HR, HRV, SpO2, stress, and respiration. It distinguishes itself from the many individual metric tools (garmin_hrv, garmin_spo2, garmin_heart_rate, etc.) by noting the simultaneous capture of all these metrics. However, it doesn't explicitly name which siblings are alternatives.

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 implies usage by noting these are 'manual measurements taken via the watch's Health Snapshot feature,' which suggests when such data exists. However, it provides no explicit guidance on when to choose this tool versus garmin_health_summary or individual metric tools, nor does it mention limitations or prerequisites.

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