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

The readOnlyHint annotation already establishes that this is a safe, non-destructive read, so the description only needs to add context. It usefully lists the returned profile fields, but says nothing about auth requirements, rate limits, or whether the data is scoped to the authenticated wearer.

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?

One sentence with the return fields front-loaded, followed by the bare endpoint reference for traceability. No filler, no repetition of the title.

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-parameter, read-only fetch with no output schema, listing the returned fields in prose compensates well for the missing return structure. Only minor gaps remain, such as the absence of any note on authentication or whether sandbox and real data are shaped identically.

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% and the single 'sandbox' parameter is thoroughly documented in the schema itself. The description mentions no parameters, which is acceptable given the schema does the heavy lifting, so the baseline of 3 applies.

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?

States a specific verb and resource ('Fetch the wearer's profile') and enumerates the returned fields, so an agent knows exactly what it retrieves. It does not explicitly contrast itself with siblings, but the resource is distinct from the webhook, document, heartrate and battery tools, so ambiguity is low.

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?

Usage is only implied by the resource name — there is no statement of when to reach for this tool versus oura_get_heartrate or other read tools, nor any prerequisites. For a zero-argument read it is adequate, but nothing is spelled out.

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