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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description's added context ('completions, matching products, and trending categories') is largely return-content detail that the output schema already carries, and it says nothing about caching, rate limits, or freshness.

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 sentences, zero filler, with the core capability front-loaded and the disambiguation sentence second. Nothing needs trimming or reordering.

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 one-parameter autocomplete tool with an output schema and annotations covering the safety profile, the description covers purpose, input nature, return content, and alternative tool. Nothing an agent needs to invoke it correctly is missing.

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 single query parameter is fully documented, so the baseline is 3. The description reinforces that the input is a partial/free-text keyword, but adds no syntax (min length, multi-word behavior) beyond the schema.

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 and resource (fetch Sephora search-box suggestions) plus the exact scope ('for a partial keyword') and what the payload contains. An agent can distinguish it from sephora_search without opening either 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?

Names the sibling sephora_search and the condition that selects it ('for paginated product results'), which clearly routes the agent. It does not state an explicit exclusion (e.g. that suggest is not for full result sets with filters), so it falls just short of the 5 bar.

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