withings_get_spo2

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

There are no annotations, so the description carries the burden of behavioral disclosure. 'Fetch' implies a read-only operation, and mentioning 'from getmeas' plus meastype 54 adds useful implementation context. However, it does not describe pagination behavior, response format, or any caveats, so the transparency is adequate but incomplete.

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 tightly written sentences with no filler. The primary purpose is front-loaded, and the routing guidance to the alternative tool is included without bloating the description.

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 fetch tool with all parameters documented in the schema and a clear alternative, the description is nearly complete. It could optionally mention the response shape or pagination behavior since there is no output schema, but the agent has enough information to call the 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 100%, so the parameters (offset, enddate, startdate) are already fully documented in the schema. The description adds no new parameter-level semantics, which matches the baseline of 3 for high schema coverage.

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?

Description states a specific verb ('Fetch'), a specific resource ('spot SpO2 measurements'), and the precise meastype 54. It also differentiates from the continuous watch SpO2 sibling tool, so an agent can immediately tell what this tool is for.

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?

Explicitly gives the alternative tool (withings_get_intraday_activity with spo2_auto) and the exact condition that should route the agent there ('continuous watch SpO2'). This leaves no ambiguity about when to choose this tool over its sibling.

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