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

With no annotations, the description carries the transparency burden. It does disclose an important behavioral trait: the tool decodes header and claims but does not verify the signature. However, it does not explain behavior on malformed input, empty input, or missing/invalid JWT structure, so transparency is only partial.

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 compact phrase that front-loads the tool's purpose and appends the key caveat. Every word adds information, with no filler or repetition.

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 one-parameter decoder with an output schema, the description covers the core behavior but leaves the q parameter unexplained and does not resolve ambiguity with the sibling jwtdecode. This is enough for a rough understanding but not fully complete for confident invocation.

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 input schema has one undocumented parameter q with 0% description coverage, and the description never mentions q. The tool name implies q is likely the JWT string, but that is left to inference, and the optional default of an empty string leaves invocation expectations unclear.

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 clearly identifies the operation (decode), the resource (JWT), and the scope (header + claims, no signature verification). It is more specific than the title alone, but it does not explicitly distinguish itself from the sibling jwtdecode, whose name suggests a very similar purpose.

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?

There is no guidance on when to use this tool versus jwtdecode, decode, or other encoding/decoding siblings. The only usage hint is the caveat 'no signature verify,' which says what the tool does not do rather than when it should be selected.

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