ai_ocr_region

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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It reveals that OCR runs through the macOS Vision framework and that returns include positions, but it omits important operational details such as screen-recording permission requirements, coordinate system/units, and behavior when no text is found.

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 two sentences with no wasted words. It front-loads the primary function and output, then adds the usage rationale in a second concise sentence.

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?

There is no output schema, so the description's 'Returns recognized text with positions' is the only return-format guidance. Important context is missing: required permissions, coordinate system, and failure behavior. For a simple 4-parameter tool this is acceptable but has clear gaps.

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%: each parameter is described as a 'Region X coordinate' or similar. The description adds 'screen region' context but does not clarify coordinate origin or units, so it provides no additional semantic value beyond the schema baseline.

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 ('Extract'), resource ('screen region'), and method ('macOS Vision framework OCR'), and specifies the output ('recognized text with positions'). It also distinguishes itself from accessibility-based siblings by noting it is for text not accessible via the accessibility API.

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 gives clear context: 'Useful for reading text that isn't accessible via the accessibility API.' This tells the agent when to prefer this tool over accessibility-based alternatives. However, it does not explicitly name which sibling tools to use instead or state exclusions, so it stops short of a 5.

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