mcp-server-devutils

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

With no annotations provided, the description carries the full burden. It discloses key behavioral traits: it decodes without verification (indicating it's a read-only, non-destructive operation) and specifies what information is shown (header, payload, expiry). However, it doesn't mention error handling for invalid tokens or output format details, leaving some gaps.

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 is front-loaded with the core purpose and includes essential details. Every word earns its place, with no wasted text, making it highly concise and well-structured.

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 tool's low complexity (one parameter, no annotations, no output schema), the description is mostly complete. It covers the purpose, behavior, and output components. However, it lacks details on error cases or exact return structure, which could be helpful for an agent, though not critical for this simple tool.

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 description coverage is 100%, with the parameter 'token' fully documented in the schema. The description adds no additional meaning beyond what the schema provides (e.g., no syntax or format details for the token). Baseline 3 is appropriate as the schema handles the parameter documentation.

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 specific action ('decode a JWT token') and resource ('JWT token'), and distinguishes it from siblings by specifying 'without verification' and listing the output components ('header, payload, expiry'). This is precise and differentiates it from potential verification 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 implies usage by specifying 'without verification', suggesting it's for inspection rather than security validation, but it doesn't explicitly state when to use this tool versus alternatives (e.g., when verification is needed) or provide exclusions. It offers some context but lacks explicit guidance.

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