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

With no annotations, the description carries the full burden of behavioral disclosure. It discloses the outputs (header, payload, expiry) but does not mention that decoding does not verify the token's signature, whether a secret is needed, or what happens with invalid input. These are important behavioral traits for an AI agent deciding between decode and verify.

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 a single efficient sentence that front-loads the operation and names the key outputs. There is no filler or repetition of schema information.

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 decode utility, the description gives the essential output information without an output schema. However, the ambiguous optional parameters and the missing note about non-verification leave clear gaps that an agent must resolve elsewhere.

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 baseline is 3. However, the schema descriptions are tautological ('Jwt to process', 'Token to process'), and the tool description adds no guidance on which of the four parameters to populate or what 'secret' is for. The coverage keeps this at baseline, but the descriptions provide little real semantics.

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 clear action ('Decode a JWT token') and specifies what is returned: header, payload, and expiry. It does not explicitly contrast with the sibling x402-jwt-verify, but the decode versus verify distinction is reasonably apparent.

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?

No guidance is given about when to use this tool versus x402-jwt-verify or any alternative. The description implies 'use this when you want to decode a JWT,' but it does not warn against using it for signature verification, which is a meaningful omission given the sibling tool.

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