read_image

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

Annotations already carry readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds value beyond annotations by disclosing the return structure (list of [metadata, image content]), the metadata fields (width/height/mime_type), the explicit non-summarization behavior, and the specific ToolFailure error codes. 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 front-loaded with the core purpose, then delivers the critical behavioral caveat (no summarization) before structured Args/Returns/Raises sections. It is well organized with minimal wasted text, though the error-enum listing adds modest length without deep explanatory value.

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 tool with no output schema, the description covers purpose, parameter, return format with metadata fields, caller responsibility, and error codes. The only notable gap is that FILE_TOO_LARGE implies a size threshold that is never specified, but overall this is reasonably complete for its low complexity.

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% (file_path is documented as '읽을 .png 파일 경로' in the schema). The description restates the parameter nearly identically without adding format, constraints, or usage nuances beyond the schema. Baseline 3 is correct when the schema carries the full parameter documentation.

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 verb (읽어...돌려준다) and resource (PNG image), and explicitly clarifies what it does NOT do (summarize the image), which separates it from document-reading siblings like read_pdf and read_docx. The purpose is unambiguous and self-contained.

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 usage context through the file-type distinction among siblings (read_pptx, read_pdf, read_svg) and clarifies that the caller must do the summarizing. However, it never names an alternative tool or gives an explicit when-to-use/when-not-to-use condition, leaving the routing to inference from the file extension.

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