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

With annotations providing no safety hints and all flags false, the description carries the full burden and does so richly: it discloses single-use behavior, a 5-minute expiry, that the response specifies the exact signing recipe, and that the tool never custodies keys. This goes well beyond what annotations alone convey and does not contradict them.

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 sentences with no wasted words. The core purpose is front-loaded, and each sentence adds a distinct piece of information: the role in the flow, the expiry and response contents, and the key ownership guarantee.

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 zero-parameter tool with no output schema, the description is complete: it explains what the response contains, why the challenge is needed, the expiry constraint, and the security context around key custody. An agent knows exactly what to expect and how to proceed after invocation.

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 schema has zero parameters and 100% coverage, so the baseline is 4. The description explicitly states 'Takes no parameters,' confirming there is no required input, which is fully consistent with the empty schema.

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 clearly states a specific verb and resource: obtaining a single-use ROLA challenge as 'Step 1 of writing to the wiki.' It distinguishes itself from siblings by explaining exactly what the response contains (the recipe for signing with an Ed25519 key) and what it does not do ('nothing here custodies anything').

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?

The description clearly frames this as the first step in an authentication flow for writing to the wiki, which implies when to use it. It does not explicitly name alternatives or exclusions, but the 'Step 1' framing and mention of your own key give enough contextual guidance.

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