Validate Uml

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

Annotations already indicate read-only, non-destructive, and idempotent behavior. The description adds meaningful behavioral context: it explicitly lists what is validated (type, format, code length, syntax) and that it returns 'errors and suggestions'. This goes beyond the annotations and clearly discloses the local nature (no remote call), without contradicting any annotations.

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 model of conciseness: two sentences front-load the core purpose and context, followed by a clear statement of the return behavior. Every word contributes; there is no filler or redundancy.

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 straightforward local validator, the description, combined with annotations and the presence of an output schema, is sufficiently complete. The tool's role is clearly delineated relative to siblings, and the description covers the essential behavior. Minor gaps about parameter behavior reduce it from a perfect score.

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 provides partial semantics by referencing 'diagram type' (diagram_type) and 'code length' (code), but omits any explanation for `strict` and `output_format`. The description does not fully substitute for the absence of schema descriptions.

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 states a specific action (validate) on a specific resource (UML diagram code) and enumerates what is validated: diagram type, format, code length, and basic syntax. It distinguishes itself from sibling generation tools by adding 'before render (no Kroki call)', clearly positioning this as a pre-render validation step.

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 phrase 'before render (no Kroki call)' clearly indicates when to use this tool as a local pre-flight check, contrasting with the generation tools. However, it does not explicitly name alternatives or state when NOT to use it, leaving some implicit nuance.

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