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

With no positive safety annotations (all false), the description carries the burden. It adds context about the interactive photo upload and availability limitation, but it doesn't disclose potential side effects (e.g., whether it changes any state) or describe what happens after the interactive session. The lack of explicit side-effect disclosure leaves some ambiguity.

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 concise sentences. The first clearly states the core functionality, and the second adds the availability caveat and fallback. No filler or unnecessary repetition.

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?

The description covers the essential context: what it does, how to get the input, availability constraints, and a fallback path. It doesn't describe the return value format, but for an interactive tool with no output schema, this may be acceptable. The description is fairly complete for a simple one-parameter tool.

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%: productRef is already described as 'Product reference token from search_products.' The description repeats this source information but adds no new parameter meaning beyond what the schema already provides. Baseline 3 applies here.

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 a specific action ('Opens an interactive virtual try-on') with a specific resource ('a product by productRef'). It also distinguishes itself from sibling tools by focusing on try-on functionality and referencing search_products for the product reference.

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 indicates when to use the tool (shopper wants virtual try-on) and provides a clear prerequisite (get productRef from search_products). It also notes an exclusions when the brand hasn't enabled try-on and offers an alternative ('viewed via its store link'), though it doesn't explicitly name a sibling tool as the alternative.

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