decode_jwt

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

No annotations are provided, so the description must carry behavioral transparency. It discloses the output content (header, payload, expiration) and implies a read-only decode operation, but it does not address signature verification, malformed token handling, or whether expired tokens still decode—important behavioral gaps for a security-related tool.

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. It states verb, object, and outcome efficiently.

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?

The tool is simple with one fully documented parameter, and the description covers the primary purpose and output categories. However, there is no output schema and the description omits edge-case behavior (invalid tokens, signature verification), leaving some ambiguity for an agent invoking the tool autonomously.

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 schema fully documents the single `token` parameter with 100% description coverage, so the description adds no extra parameter semantics beyond naming the JWT token. Baseline 3 is appropriate.

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 'Decode' and a specific resource 'JWT token', and states the outcome ('to see its header, payload, and expiration'). This clearly distinguishes it from sibling encode/hash tools.

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 clear context: use this tool when you need to inspect the header, payload, or expiration of a JWT. It does not explicitly name alternatives or exclusions, but the JWT-specific scope is sufficient guidance.

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