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

readOnlyHint=true already establishes the safety profile, so the description's job is to add context — it does so by disclosing the returned fields (org, practitioner, expiry). It doesn't say what happens when the key is expired or invalid, which is the main behavioral risk for a credential-scoped call.

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?

Three short fragments, return content stated first and the usage hint second — well front-loaded with zero filler. The clipped verbless phrasing is slightly terse but never ambiguous.

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 zero-parameter, read-only endpoint with no output schema, the description supplies enough: what identity is returned and that it reflects the API key's owner. Only the expired/invalid-key behavior is left implicit.

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?

The tool takes no parameters, so the baseline is 4; there is nothing for the description to compensate for.

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 names the resource returned (the organisation and owning practitioner plus key expiry) and the endpoint (GET /me), which clearly distinguishes it from sibling lookups like splose_get_practitioner or splose_list_practitioners. It is a noun-phrase rather than an explicit verb, but the intent 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?

'Good first call' tells the agent to use this at the start of a session to establish identity/tenancy and confirm credentials work. No exclusions or alternatives are named, but for a zero-parameter identity endpoint there is little sibling overlap to disambiguate.

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