Decode

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

With no annotations, the description carries full responsibility for behavioral disclosure. It fails to mention any behavioral traits such as read-only status, error handling (e.g., invalid input), or side effects. The description only states the action, omitting safety or operational context.

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 concise at one sentence, but it is too brief to cover the necessary information. It front-loads the purpose but sacrifices completeness. Every sentence should earn its place; here, the single sentence could be expanded without losing conciseness.

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?

Given the presence of 3 parameters (including an unexplained 'variant') and no output schema, the description is incomplete. It does not explain what the tool returns, how the variant affects decoding, or any limitations. The minimal description leaves significant gaps for an agent.

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 0%, so the description must compensate. It lists the possible methods but does not explain the 'data' parameter beyond context, and the 'variant' parameter is entirely undocumented. The description adds minimal meaning beyond the enum values already in 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?

The description clearly states the verb 'decode' and the resource 'data' using various methods, listing them explicitly. It distinguishes from the sibling 'encode' tool by name and action. However, it does not explicitly position itself as the decoding counterpart, missing a slight opportunity for clarity.

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 no guidance on when to use this tool versus alternatives like 'encode' or 'jwt-encode'. It does not mention prerequisites, when-not-to-use, or any context for selection, leaving the agent to infer usage solely from the name.

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