Find text (OCR)

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

With no annotations, the description carries the burden. It discloses the core behavior (OCR, bounding boxes, optional filtering) and even suggests a specific tap mode. It omits details like coordinate format or error handling, but for a read-only OCR tool it is reasonably transparent.

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?

Three sentences, each earning its place: the main function, the differentiator, and a usage callback. It is front-loaded and free of fluff.

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 no output schema or annotations, the description covers the essential use case well, including return type and tap integration. The only notable gap is the undocumented confidence parameter, but overall the tool is understandable and usable from the description alone.

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 schema describes query and device_id well, but min_confidence lacks any explanation beyond a default. The description does not mention min_confidence at all, leaving its meaning and impact unclear. With 67% schema coverage, the description should compensate but doesn't.

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 OCRs the current screenshot and returns on-screen text with pixel bounding boxes. It explicitly contrasts with the accessibility tree, distinguishing it from sibling tools like find_elements.

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?

It explicitly notes this is for elements the accessibility tree misses, giving clear when-to-use guidance. It also advises how to interact with results via tap{text, ocr:true}, which is practical and actionable.

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