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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds a useful detail: maxTokens truncates content to fit. Otherwise it has no return-shape or error behavior notes, which is a modest but real gap.

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?

Three sentences, front-loaded with what it returns and the topic list, then usage mode, then a caveat about maxTokens. Efficient and scannable, with no wasted clauses.

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 read-only lookup tool with 100% schema coverage and no output schema, this is complete enough: the agent knows what comes back conceptually, how to select inputs, and when to invoke it. The remaining gap is lack of sibling disambiguation against other principle/guide tools.

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 all three parameters, including aliases and recommended maxTokens range. The description reinforces the semantics of topic, query and maxTokens in-line, adding marginal value beyond the schema baseline.

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 verb+resource: returns Better Design's visual design principles, and enumerates the covered topics (hierarchy, spacing, typography, color, etc.). It distinguishes itself from get-ux-principle and get-motion-guide in substance but never names those siblings.

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 a clear usage trigger ('use it when the user wants to know how an interface should look') and explains how to pick inputs (topic vs query vs nothing). It does not explicitly contrast with sibling principle tools like get-ux-principle or get-motion-guide, leaving the agent to infer the boundary.

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