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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering safety and non-determinism. The description adds allowed formats and a cost note ('60 points per call'), but it does not disclose much beyond that; the 'upload an image' wording also conflicts slightly with the URL-based input in the schema. No contradiction with 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?

The description is compact and front-loaded with the core action, then adds format/cost constraints. The Korean sentence largely restates the English part with a slightly expanded output list, introducing minor redundancy, but overall it remains appropriately sized.

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 one-parameter read-only tool, the description covers the purpose, a broad output description, and constraints. However, because there is no output schema, it should do more to describe what the returned labels or pages look like, and it never clarifies that the 'upload' is actually a URL reference rather than a file upload.

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%, and the schema already documents the downloadable https URL, allowed MIME types, and 50MB limit. The description only reiterates the image-format restriction and does not add meaning beyond schema, so it meets the baseline for a fully covered schema.

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 opens with 'Reverse image search' and clearly states the action: provide an image and get visually matching web pages and labels. It is specific about verb and resource, but it does not distinguish itself from the sibling google_image_search, which appears to serve a very similar purpose.

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 use case is implied by 'reverse image search' and the Korean phrase '이미지로 검색', and the only exclusion is that only image-format files are allowed. There is no explicit guidance on when to prefer this over google_image_search, google_search, or image_similarity, so an agent must infer the appropriate context.

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