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

Annotations already mark the tool as read-only and non-destructive, so the description's 'Build' and 'return' are consistent. The description adds a critical behavioral requirement: confirm the profile with the shopper before showing products. This goes beyond annotations and is essential for correct invocation. No contradictions found.

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 two sentences with no wasted words. The primary purpose is front-loaded, and the required confirmation is clearly highlighted with 'REQUIRED'. It is concise while conveying both the action and a critical constraint.

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?

Given the presence of annotations, a comprehensive input schema, and an output schema, the description covers the essential aspects: purpose and the mandatory confirmation step. It does not need to detail return format or parameter syntax. The only minor gap is the lack of alternative routing, but that falls under usage guidelines. Overall, it is sufficiently complete for an agent to call it correctly.

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 all four parameters are documented in the schema itself. The description only references 'free-text description' (matching skin_description) but does not elaborate on avoid, goals, or tenant_id. Since the schema carries the semantic load, a baseline 3 is appropriate; no additional meaning is provided.

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 clearly states the tool's function: building an AI skin profile from free-text and returning matched sponsored products. It is specific about the input and output, distinguishing it from general product search or profile builders. However, it does not explicitly differentiate from sibling tools like sponsored_search, so it falls short of a 5.

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 includes a REQUIRED step (confirm profile with shopper before showing products), which is a usage directive during execution but not about when to select this tool versus alternatives. It provides no guidance on when to use skin_match over siblings like sponsored_search or routine_builder. There are no explicit exclusions or conditions.

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