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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds the point cost and reiterates the image-format restriction, but does not describe behavioral details like error handling, pagination, or result format. It adds marginal value beyond the annotations.

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 concise sentences, with the primary purpose front-loaded in English and repeated in Korean. The duplication is minor but not harmful. It is efficient and easy to scan.

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 single-parameter, read-only tool with annotations and full schema coverage, the description provides the essential purpose and the format constraint. It mentions the output (web pages and labels) without detailing structure, which is acceptable for a simple reverse image search tool. Complete enough 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?

The schema covers 100% of the parameter (image_url), including URL format, acceptable image types, and size limit. The description adds no new semantic meaning beyond what the schema already provides, so a baseline of 3 is appropriate.

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: reverse image search via image upload, returning visually matching web pages and labels. It distinguishes itself from text-based search siblings like google_search and google_image_search by explicitly framing it as 'reverse image search' with an image input.

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 implies the use case — when you have an image and want to find matching web content — providing clear context. However, it does not explicitly mention alternatives or when not to use it, so it lacks the explicit exclusion of sibling tools that would merit a 5.

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