native-view-at-point

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

With no annotations, the description fully discloses key behavioral traits: coordinate system (raw iOS points, not normalized), the distinction from touch-interactive queries, and the restart_required status condition. It does not explicitly state that the operation is read-only or non-destructive, but that is implied by 'inspect'. Slightly more detail on side effects could push to 5.

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 extremely concise: 5 sentences, no wasted words. It front-loads the core purpose, then adds contrast, important caveats, and recovery instructions in a logical order. Every sentence earns its place.

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 10 parameters, 4 required, no output schema, and no annotations, the description covers the tool's primary distinction, coordinate system, and error handling. It does not describe the output structure, but the schema with fields parameter implicitly defines return content. A minor gap is not explaining parameters like maxDepth or skipClasses, but these are well-documented in the schema. Overall adequate for effective use.

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 coverage is 100%, so baseline is 3. The description adds significant value by emphasizing the critical coordinate distinction for x and y: 'raw iOS window coordinates in points, NOT normalized [0,1] simulator tap coordinates.' This reinforces and extends the schema's own description, earning a 4.

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's purpose: 'Inspect the deepest visible UIView at a raw native window point.' It explicitly distinguishes itself from the sibling 'native-user-interactable-view-at-point' by highlighting that it ignores userInteractionEnabled, making its scope well-defined.

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 provides explicit guidance on when to use this tool versus the alternative: answers 'what is visually here?' rather than 'what would receive the touch?'. It also includes important coordinate system caveats and a specific error recovery action ('If status is restart_required: call restart-app then retry.'), leaving no ambiguity.

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