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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds that it uploads an image and uses a temporary URL, which is useful context, but does not disclose further behavioral details (e.g., statelessness, external calls). Given the annotations, a 3 is appropriate as the description adds some value but not a rich behavioral layer.

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 a single, front-loaded sentence with no extraneous information. It states the core action and expected return in a compact, efficient manner.

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 function, input requirements (local image or base64), and output contents (products with sizes, pricing, URLs). With an output schema present and high schema coverage, no critical information is missing for an agent to call the tool 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?

The schema provides descriptions for all 14 parameters (100% coverage), so the baseline is 3. The description only reiterates the image input options (local file or base64) which are already in the schema, adding minimal value beyond what the schema already provides.

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 states a specific action: upload a local image file (or base64) and search PoloPan products, clearly distinguishing it from text or URL-based search siblings. It also specifies what is returned (in-stock sizes, pricing, verified purchase URLs), leaving no ambiguity about the tool's core function.

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 clearly implies usage when you have a local image (file path or base64) and want to search by image. It does not explicitly mention when not to use it or contrast with siblings like image_url, but the context of uploading a local file is clear and sufficient for most agents to select the right tool.

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