evaluate_design

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

The annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds that the tool produces principles, violations, and improvement suggestions, but it does not add behavioral detail such as output size, the meaning of compact mode, or the before/after diff behavior. No contradiction with annotations exists.

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 tight sentence with no filler, front-loading the core action and then listing the three output categories. It earns its place and avoids duplicating schema details.

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?

With six optional parameters and no output schema, the description leaves important context implicit: it does not explain whether a text description, screenshots, or both are needed, nor does it describe the structured pixel diff returned when both before and after screenshots are supplied. The compact mode payload rationale is only present in the schema, not reflected in the description, so an agent has to infer key invocation behavior.

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%, so the schema already documents each parameter clearly. The main description adds no new parameter-level semantics beyond the general 'evaluate design' idea. This fits the baseline score of 3 for a tool whose schema has fully documented parameters.

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 uses the specific verb 'Evaluate', names the resource ('design description'), and binds the operation to 'UX principles'. It also states the return contents: relevant principles, potential violations, and improvement suggestions. It does not explicitly distinguish itself from the many audit_* siblings, but the wording is specific enough that an agent can infer its intent.

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?

There is no guidance about when to choose evaluate_design over the many related audit_* or get_* tools. No conditions, exclusions, or alternative tool names are mentioned, so an agent must infer the appropriate context from the tool's name and generic description.

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