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

Annotations already indicate it's a write operation (readOnlyHint false). The description adds cost ($0.10) and API key requirement, which are not in annotations. It does not disclose behavior like error handling or side effects of missing fields, but the bar is lower with annotations present.

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 very short and front-loaded with the core action. It is not verbose, but it sacrifices necessary detail. The structure is efficient but lacks completeness.

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?

With 9 parameters and low schema coverage, the description is too brief. It does not explain parameter semantics, usage conditions, or potential pitfalls. The output schema exists, but the description is insufficient for an agent to call this tool 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?

Schema description coverage is only 22%, so the description should compensate. It only mentions sleep_id but does not explain its format or the meaning of other parameters like quality, timezone, or sleep_type. The description adds minimal value beyond the schema.

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 action (patch), the resource (sleep record), and the identifier (sleep_id). It distinguishes from siblings like log_sleep (create) and get_sleep (read) by specifying 'existing sleep record'.

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?

It implies usage for existing records, which separates it from creation tools. However, it does not explicitly name alternatives or state when not to use it. The context is clear but lacks explicit exclusion criteria.

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