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

Beyond the readOnly/openWorld annotations, the description discloses two genuinely useful behaviors: page-based pagination and the non-obvious quirk that Sephora's search never returns a true zero-result state for a nonempty keyword. This is exactly the kind of upstream quirk that prevents an agent from misreading empty-looking results. It stops short of noting rate limits or result caps.

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, front-loaded with the core action and free of padding; the trailing quirk sentence earns its place by preventing a misread of results. The first sentence is dense with enumerated features but remains readable.

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 10-parameter search tool with an output schema and read-only annotations, the description covers the essentials: scope, pagination, filters, and the zero-result quirk. Return-value details are correctly left to the output schema, so nothing critical 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%, so the schema already documents all ten parameters including price pairing and facet syntax. The description reinforces filter categories and combinability but adds no syntax, format, or constraint detail beyond what the schema provides. Baseline 3 applies when the schema does the heavy lifting.

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 ('Search') and resource ('Sephora's product catalog by keyword') and enumerates the supported refinements (pagination, sort, price range, brand/rating/is-new/facet filters). It does not, however, differentiate itself from siblings like sephora_suggest, sephora_category, or sephora_product, leaving the agent to infer which entry point to use.

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?

The description lists capabilities but gives no explicit when-to-use guidance or named alternatives among the eight sibling sephora_* tools. An agent gets an implied sense that this is the keyword search entry point, but nothing states when to prefer sephora_suggest or sephora_category instead.

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