ocr_message_images

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

With no annotations, the description carries full behavioral disclosure. It mentions using macOS Vision and the opt-in requirement, but fails to disclose any side effects, output behavior, or the significance of the 'allow_derived_write' parameter. The description does not mention whether the tool can write data, which is a critical behavior given the parameter.

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 fluff, and it front-loads the core purpose. However, it is so brief that it omits essential parameter and usage context, which slightly reduces efficiency. Every word earns its place, but more detail would improve overall usefulness.

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?

The tool has five parameters, no annotations, and no schema descriptions, yet the description provides only a one-line summary. It lacks essential context about parameter meaning, side effects (especially 'allow_derived_write'), output formatting, and when this tool is preferred over siblings. For a moderately complex tool, this is insufficient.

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 0%, and the description itself provides no explanation of the five parameters. It does not clarify what 'chat', 'local_id', 'server_id_str', 'languages', or 'allow_derived_write' mean. The agent would have no guidance on how to populate these parameters beyond their names.

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 performs OCR on readable local images using macOS Vision, which is a specific action and resource. It does not explicitly differentiate from sibling tools like transcribe_message_voice or message_media, but the OCR function is distinct enough. The mention of opt-in requirements adds context.

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 when to use the tool (when you need OCR on local images) and provides a clear prerequisite ('explicit MEDIA and OCR opt-in required'). However, it does not provide alternatives or exclusions, such as 'use extract_message_files for non-OCR tasks' or 'not for remote images'. The guidance is contextually clear but lacks explicit comparison to siblings.

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