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

Adds useful behavioral details beyond annotations: returns {mermaid, validation_errors, structural_warnings}, 'Bad input returns validation_errors with mermaid=null; it never raises', and lists validation checks. It does not disclose side effects despite readOnlyHint=false, but no direct contradiction arises.

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 long but dense, covering purpose, workflow, input structure, and error handling in a structured way. It front-loads the core action and uses the rest for necessary detail, so it is efficient despite length.

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 complex tool with nested objects, the description covers workflow context, input schema details, return values, and error behavior. It leaves no significant gaps for an agent to select and invoke the tool correctly.

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 100% and the description mirrors the schema's artifact structure almost exactly. It adds no new parameter semantics beyond what the schema already provides, so the baseline 3 is appropriate.

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 opens with 'Validate a DFD artifact and render it as styled Mermaid,' which is a specific verb+resource. It clearly distinguishes itself from siblings by referencing the DFD specialist workflow and submit_response, positioning it as the validation/rendering 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?

Explicitly states when to use: 'after the DFD specialist has finished extraction' and 'before the artifact is submitted via submit_response'. This gives clear workflow context. However, it does not name alternative tools or explicitly state when not to use it, so it falls short of a 5.

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