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

Annotations already provide readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds the non-obvious behavioral detail that it returns an interactive chart plus a short summary, rather than raw JSON. No contradictions with annotations were found.

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 tight sentences: the first covers purpose and ranges, the second covers return value. There is no filler or redundant restating of the tool name. Every sentence 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 chart tool with one optional parameter, an output schema, and clear annotations, the description is complete. It specifies the visual nature, the selectable time windows, and the expected return shape. Nothing an agent needs to invoke it correctly is missing.

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 100%, so the range parameter and its default are already fully documented. The description repeats the allowed values without adding additional syntax, format, or edge-case guidance. Per baseline, a 3 is appropriate when the schema handles parameter semantics.

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 states a specific verb (visualize/show) with a clear resource (sleep duration and score trend) and scope (7d, 30d, 90d, or 1y). This distinguishes it from list_sleep and show_sleep_detail, which imply raw or detailed views. The 'interactive chart plus short summary' makes the visualization purpose unambiguous.

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 phrase 'Visual sleep duration and score trend' clearly signals when this tool is appropriate: when the user wants a chart/trend rather than raw sleep data. It does not explicitly mention alternatives like list_sleep or show_sleep_detail, but the visual-vs-list/detail distinction is strongly implied by the wording.

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