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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered; the description adds a genuinely useful behavioral fact by stating 'Requires a bearer token' (auth prerequisite). It does not disclose rate limits or pagination, but that is a minor gap against annotation coverage.

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 short sentences with no filler, and the highest-value content (what you get back) is front-loaded ahead of the API mapping and auth note.

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?

With no output schema, the description carries the burden of describing the return and does so by listing the fields returned. Auth is covered, annotations cover safety, and there are no parameters, leaving only minor ambiguity around how this differs from recent_postcards.

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 zero parameters, so the baseline is 4. The description adds no parameter information because none exists to add.

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 a specific resource (the caller's own profile) and enumerates its contents: handle, status, sites, and last 20 postcards. It is clearly distinct from write siblings like post_postcard, but it does not explicitly contrast itself with the overlapping recent_postcards, so it falls short of a 5.

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?

There is no when-to-use or when-not-to-use guidance and no alternative named, even though recent_postcards appears to overlap with the 'last 20 postcards' this tool returns. The only routing help is the 'Same as GET /api/me' API mapping.

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