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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuine behavioral context by disclosing the ranking mechanism and that results come with explanations for why each site is close. It doesn't mention result count limits or ordering ties, which keeps it from a 5.

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?

Two tight sentences: use case first, mechanism second, exclusion last. Every clause carries information and the routing hint is front-loaded.

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 three-parameter read tool with no output schema, the description covers when to call, how ranking works, and that explanations accompany results. A brief note on what the result list looks like (or the default cap of 5) would close the remaining gap.

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 67%, with site's accepted formats and by's enum already documented. The description adds real meaning by clarifying that "overall" is the mean of palette/type/layout distances, which the schema does not say. The limit parameter remains unexplained in both places.

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 action and resource: ranks indexed sites by an explainable distance on palette, type, or layout. The example phrasings ("more like Linear", "sites with Stripe's typography") make the intent unmistakable and distinct from search_designs.

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?

Explicit when-to-use condition (user likes one site and wants alternatives or neighbours) and an explicit exclusion routing free-text queries to search_designs. Nothing is left to inference about which sibling to pick.

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