touch

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions the need for precise coordinates from 'describe_ui,' which adds useful context about dependencies, but it doesn't disclose other behavioral traits such as whether this is a read-only or destructive operation, error handling, or performance implications. For a tool with 6 parameters and no annotations, this is a significant gap in transparency.

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 appropriately sized with two sentences that are front-loaded and efficient. The first sentence states the purpose, and the second provides usage guidance, with zero wasted words, making it highly concise and well-structured.

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 the complexity of a UI automation tool with 6 parameters, no annotations, and no output schema, the description is incomplete. It lacks details on behavioral traits, parameter explanations, and expected outcomes, making it inadequate for an agent to fully understand how to invoke the tool correctly in this context.

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%, meaning none of the 6 parameters have descriptions in the schema. The description mentions 'coordinates' (hinting at x and y) and 'touch down/up events' (hinting at down and up), but it doesn't explain parameters like delay, simulatorUuid, or the exact usage of boolean flags. It adds minimal meaning beyond the bare schema, failing to compensate for the low coverage.

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 'touch down/up events at specific coordinates,' which is a specific verb+resource combination. However, it doesn't explicitly distinguish this from sibling tools like 'tap,' 'long_press,' or 'gesture,' which likely have overlapping functionality in the UI automation context, so it doesn't fully differentiate from alternatives.

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 clear context on when to use this tool by advising to 'Use describe_ui for precise coordinates (don't guess from screenshots),' which gives practical guidance. However, it doesn't specify when to use this tool versus alternatives like 'tap' or 'gesture,' or any exclusions, so it lacks explicit alternative naming or when-not-to-use instructions.

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