request_challenge

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

With no annotations, the description carries the full burden. It discloses the return fields (ID, prefix, difficulty, expiration) and the solving requirement (SHA-256 with leading zero bits). It does not mention side effects, rate limits, or authorization needs, but for a simple request tool, these omissions are acceptable.

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?

The description is extremely concise, using two short sentences plus a sentence about solving. It is front-loaded with the action and resource, and every sentence adds value. No redundancy or unnecessary words.

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?

Given the tool's simplicity (no parameters, no output schema), the description fully explains what it returns and how to use it. It ties directly to the sibling 'register_agent', completing the context. No 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 has zero parameters, so schema coverage is 100% by default. The description does not need to add parameter details beyond the schema, which is empty. It instead explains the return value structure, which is appropriate here. Baseline for 0 params is 4.

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 the tool requests a proof-of-work challenge for agent registration. The verb 'request' and resource 'challenge' are specific. It distinguishes from the sibling 'register_agent' by framing it as a prerequisite, making the purpose 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?

The description explicitly says 'for agent registration' and instructs the user to pass the result to 'register_agent', providing clear usage context. While it doesn't state when not to use it or alternative tools, the linkage to registration is sufficient for the agent to determine appropriate invocation.

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