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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds operational details beyond annotations: a $0.05 cost and the need for an API key. This is valuable transparency for an agent deciding whether to invoke the tool. No contradictions with annotations.

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 a single, tight sentence that front-loads the core function ('Sleep: day/week/month totals and averages') and then adds cost and auth requirements. There is no fluff; every phrase earns its place.

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?

For a simple read-only summary tool with one parameter and an output schema, the description covers the essential context: operation, time ranges, and operational constraints (cost, API key). Return format is delegated to the output schema, which exists. It is complete enough for an agent to call correctly without ambiguity.

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 single parameter 'range' has an enum (day, week, month). The description indirectly references this via 'day/week/month totals and averages', giving context to the parameter. However, with 0% schema description coverage, the description carries the burden, and it adds minimal detail beyond the enum values themselves. Adequate but not rich.

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 a specific function: retrieving sleep totals and averages for day, week, or month ranges. It implies a summary view, distinguishing it from sibling get_sleep (likely raw logs) and log_sleep (write), though it doesn't explicitly name 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?

No guidance is given on when to use this tool versus alternatives like get_sleep or log_sleep. The only contextual hints are cost and API key requirements, which are operational constraints rather than usage guidance. The description does not specify conditions for choosing summary over raw data.

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