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

Annotations already declare readOnlyHint=true, lowering the burden, and the description adds genuine context beyond that: it discloses the underlying REST call and what the result is good for (credential/subdomain verification). It doesn't describe the response payload shape, but for a zero-param whoami that is minor.

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, front-loaded with the core action and followed by a one-clause rationale. No filler or redundancy.

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 trivial read-only, zero-parameter tool with no output schema, the description covers purpose, usage rationale, and endpoint — everything an agent needs to invoke it correctly. No meaningful gaps remain.

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 schema has nothing to explain and the description correctly offers none. Baseline of 4 applies for a parameterless tool.

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 ('Return the currently authenticated user'), which cleanly distinguishes it from siblings like zendesk_get_user (by id) and zendesk_search_users. The endpoint reference (GET /users/me.json) reinforces the exact scope.

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?

Gives a clear use context — 'a quick way to verify credentials and subdomain' — which tells the agent when this tool is the right pick rather than fetching a specific user. It does not explicitly name or exclude the sibling alternatives (e.g. zendesk_get_user), so it stops short of a 5.

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