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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, but the description still adds real value: it clarifies the tool returns reference data and does NOT evaluate the design, and that the kit's copy-ready prompt is deliberately omitted with kit_prompt_url as the human-facing substitute. That discloses scope limits the annotations cannot express.

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?

Front-loaded with purpose, then usage, then the return shape. The inline JSON return sketch is bulky, but with no output schema it earns its place by telling the agent exactly what comes back and which fields are omitted.

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?

No output schema exists, so the description carries return-shape documentation and does so thoroughly (field-by-field), while also covering optional-input behavior and the intentional omission of the agent prompt. An agent has everything needed to call and interpret it.

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 coverage is 100%, so the baseline is 3, but the description adds meaning beyond the schema: the four optional params are merely recorded into an `inputs` echo and do not alter the rubric, and `rules` defaults to the current contract version. That behavioral framing is genuinely informative.

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?

States a specific verb+resource ('Get the Designesy Design Review rubric'), enumerates the eight dimensions, and explicitly contrasts itself with designesy_score. An agent can distinguish it from all 17 siblings without opening a schema.

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?

Gives explicit when-to-use ('structured rubric to critique a design holistically') and a dedicated when-NOT-to-use clause naming the alternative tool (designesy_score) for numeric scoring. Nothing is left to inference.

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