mcp-server-devutils

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states what the tool does but doesn't explain what validation entails (e.g., syntax checking, semantic validation, error messages), whether it's read-only or has side effects, or any performance or security considerations. This leaves significant gaps for an agent to understand the tool's behavior.

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 extremely concise at just three words, front-loading the core purpose with zero wasted text. Every word earns its place, making it easy to parse quickly.

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 (single parameter, no output schema, no annotations), the description is minimally adequate but incomplete. It states the purpose but lacks behavioral details and usage context, which are important for a validation tool that likely returns success/failure or error information.

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 single parameter 'expression' fully documented in the schema. The description doesn't add any additional meaning beyond what the schema provides (e.g., format examples, validation rules), so it meets the baseline score of 3 for high schema coverage.

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 'Validate a cron expression' clearly states the verb ('validate') and resource ('cron expression'), making the purpose immediately understandable. However, it doesn't explicitly differentiate from sibling tools like 'cron_explain' or 'cron_next', which prevents a perfect score.

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. There are sibling tools like 'cron_explain' and 'cron_next' that work with cron expressions, but the description doesn't mention any context, prerequisites, or exclusions for choosing this validation tool.

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