extract_text_from_image

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

The description discloses the core behavior (OCR, verbatim transcription) and the parameter format, which gives agents some sense of what to expect. However, with no annotations provided, it does not disclose potential limitations (e.g., image format support, accuracy issues) or side effects, leaving a gap in behavioral transparency.

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 short and front-loaded with the tool's purpose and a mandatory-call directive. The Args section is clear and direct. Minor redundancy exists with the '必须调用' phrase appearing twice, but it does not significantly detract from the structure.

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 tool's simplicity (single parameter), the description covers purpose, usage, and parameter semantics well. An output schema exists, so return details are not required. It lacks discussion of edge cases like unsupported image types or error handling, but for a straightforward OCR tool, the description is reasonably complete.

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 input schema provides no description for the 'image' parameter (0% coverage). The description fully compensates by stating the parameter accepts a local absolute file path or an http(s) URL, explicitly defining the valid formats. This is essential for correct invocation.

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 explicitly labels the tool as an OCR tool and states it transcribes all text in an image verbatim, with suitable use cases listed (screenshots, documents, code, receipts). The directive '必须调用' (must call) reinforces its specific role, clearly distinguishing it from the sibling tool 'look_at_image', which handles visual inspection rather than text extraction.

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 provides an explicit when-to-use rule: it must be called whenever a user uploads an image requiring text extraction. However, it does not mention when not to use the tool or explicitly compare it to 'look_at_image', so it stops short of full alternative guidance.

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