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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered by structured data. The description adds the useful concept of single-use enforcement, but does not describe the result semantics (spent vs. unspent) or any failure/auth behavior, so it adds only modest value beyond the annotations.

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?

A single, front-loaded sentence with no filler; the purpose and the key semantic qualifier are stated immediately.

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?

There is no output schema, and for a status-check tool the description never indicates what the check returns (e.g., spent/unspent flag) or what a negative result implies. The safety profile is covered by annotations, but the return-value gap leaves it only minimally complete.

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 100%, so the schema documents both parameters, and the baseline is 3. The description adds nothing about the 'digest' format or the generic 'query' object, so it does not go beyond the 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?

States a specific verb ('Check') and resource ('whether a proof digest has already been spent'), and the parenthetical '(single-use enforcement)' clarifies the semantic meaning of 'spent'. It does not explicitly differentiate itself from the close sibling affix_spent_revoke, 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?

The phrase '(single-use enforcement)' hints at the use case (verifying a digest has not been consumed before accepting it), but there is no explicit when-to-use, when-not-to-use, or named alternative. Usage is only implied.

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