Tap element

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

Annotations indicate readOnlyHint=false and destructiveHint=false, so the tool is not read-only but not destructive. The description adds the behavior of tapping the center coordinate, but does not disclose what happens if no element is found, whether it waits for the element, or if multiple matches cause an error. Beyond the annotations, the description provides minimal behavioral context.

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 concise sentence, front-loaded with the action. It contains no redundant words. While it is short, it is appropriately sized for a simple command, though it could have added more detail without becoming verbose.

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 tool's complexity (12 parameters, multiple possible selectors, no output schema), the description is severely incomplete. It provides no information on parameter combinations, required vs optional, behavior with multiple matches, or error handling. The description is insufficient for an agent to reliably use the tool correctly beyond the simplest case.

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?

With 12 parameters and 0% schema description coverage, the description must compensate by explaining how parameters are used. It does not. The description only says 'Find an element' without indicating that parameters like text, class, or resourceId are used as locators. No parameter semantics are added beyond the raw schema property 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's function: find an element and tap its center coordinate. This specifies the verb (tap), resource (element), and method (center coordinate), distinguishing it from a generic coordinate-based tap. However, it does not explicitly distinguish from the sibling tool 'tap' or mention the element-finding mechanism.

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 no guidance on when to use this tool versus alternatives like 'tap' or 'findElement'. There is no mention of prerequisites, expected scenarios, or exclusions. The usage context is only implied by the tool name and description.

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