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

With no annotations, the description must disclose behavioral traits. It clearly states the operation is free, has no side effects, does not evict the cache or touch relays, indicating a safe read-only check. It could be more explicit about the return value (e.g., boolean), but the output schema likely covers this. Score reflects good transparency with minor omission.

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, with two sentences. The first sentence immediately states the purpose, and the second provides usage context and safety. Every sentence earns its place with no 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?

For a simple check tool with 2 parameters and an output schema, the description covers purpose, usage scenario, and behavioral traits. It doesn't detail prerequisites or output format, but the schema and output schema suffice. Score 4 indicates it is nearly complete for the tool's complexity.

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 coverage is 100%, so baseline is 3. The tool description does not add new information about the parameters beyond what the schema already provides (both are described as required with specific formats). The description adds context about the npub-proof flow, but that is incidental to parameter meaning. Score stays at 3.

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 uses a specific verb ('Check whether') and clearly identifies the resource (validity of a cached dpop_token). It distinguishes from sibling check tools by explicitly mirroring 'check_oauth_status' for the npub-proof flow, providing clear differentiation.

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 a concrete use case: ask if a dpop_token will be accepted before a paid call to avoid wasting credits. It states the tool is free and has no side effects. While it doesn't explicitly list when not to use it, the mirroring hint offers some guidance. A score of 4 reflects clear context with room for explicit exclusions.

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