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

The description supplements the annotations with important behavioral details: the returned token expires in fifteen minutes, is single-use, and challenges cannot be reused. These details clarify the non-idempotent and mutating nature implied by the annotations without contradicting 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?

Four sentences deliver dense, relevant information without wasted words. The purpose and workflow step are front-loaded, followed by essential compute details, token constraints, and the next action.

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 two-parameter tool with an output schema present, the description covers the essential behavioral context: how to construct a valid nonce, token validity and usage, challenge reuse constraints, and the next workflow step. No critical guidance appears missing.

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?

Schema description coverage is 0%, so the description must compensate. It explains the nonce parameter well ('Find a nonce such that sha256(prefix + nonce) starts with the required number of hexadecimal zeros'), but the challenge_id parameter is only indirectly referenced as 'a challenge already spent,' leaving its origin and role reliant on workflow context rather than explicit description.

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 states a specific action ('Trade a valid nonce for a token') and clearly identifies the resource and output. It also differentiates itself from siblings by marking it as 'Step 2 of 3' and naming the next call, submit_application.

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 provides strong contextual guidance by positioning the tool in a multi-step workflow ('Step 2 of 3', 'Next call: submit_application'). It also warns about a key condition ('A challenge already spent cannot be reused'), but does not explicitly discuss alternatives or when not to use this tool.

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