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

No annotations are provided, so the description carries the full burden. It discloses the core behavior (runs OCR, returns text) and the input encoding, but does not mention side effects, limits, supported image formats, or whether the operation is read-only. For a simple read-only tool, this is adequate but minimal.

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 sentence with no wasted words. It is front-loaded with the action and resource, making it easy for an agent to scan and understand quickly.

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 simple 2-parameter tool with a complete schema and an output schema, the description is nearly sufficient. It omits minor details like supported image formats or error cases, but these are not critical for correct invocation.

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%, so the baseline is 3. The description adds 'base64-encoded bytes' which duplicates the schema's image_base64 description and does not provide additional meaning for the lang parameter. No extra parameter-level value is added.

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?

States a specific verb ('Run OCR') and resource ('image'), and specifies input format (base64-encoded bytes). It clearly distinguishes from siblings like parse_spreadsheet, pdf_to_markdown, and url_to_clean_text by focusing on image OCR.

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 when OCR on an image is needed, but does not explicitly state when to use this tool versus alternatives, nor mention exclusions or conditions. The sibling tools are present but not referenced, leaving selection to inference.

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