get_sleep

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

No annotations are provided, so the description carries the behavioral disclosure burden. It does disclose useful behavior: it returns sleep stages, duration, score, and related metrics, and defines the night boundary. However, it does not mention timezone handling, missing-data behavior, or any other edge-case behavior, leaving some behavioral ambiguity.

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 two tight, front-loaded sentences with no filler. The main purpose and return contents come first, followed by the parameter detail in a compact Args block. 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 single-optional-parameter getter with no output schema, the description adequately covers purpose, return contents, date semantics, and parameter format. It stops slightly short of being fully complete by not addressing timezone sensitivity or what happens when no sleep data exists, but those are minor for this simple 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?

Schema coverage is 0%, but the description fully compensates by documenting date_str as 'Date as YYYY-MM-DD' and stating 'Defaults to today.' Despite the schema default being null, the description clarifies the effective default and format, which is exactly what an agent needs to invoke the tool correctly.

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 uses a specific verb and resource: 'Get sleep data for the night ending on the given date' and enumerates the returned content (sleep stages, duration, sleep score, related metrics). No sibling tool overlaps with sleep data, so the purpose is 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 description clearly frames when the tool applies: retrieving sleep data for a particular night, with date boundaries specified by 'night ending on the given date' and a default of today. No explicit exclusions or alternative-tool routing are needed since no sibling covers sleep, though the description could have been more explicit about when not to use it.

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