ui_find_element

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a safe read operation. The description adds that it returns tap coordinates, which is useful behavioral context. However, it doesn't disclose details like whether partial matches are default behavior, how many results are returned, or what happens with multiple matches - though exactMatch parameter partially covers matching behavior.

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?

Two tight sentences with zero waste. The first sentence states the purpose and search criteria, the second describes the return value. Every clause carries meaning.

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 that an output schema exists (documenting the return structure) and annotations flag this as read-only/open-world, the description covers the essential aspects: what it finds, how to search, and what it returns. The tool is relatively simple with good schema coverage, so the description is adequately complete for its complexity level.

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 all 6 parameters are well-documented in the schema itself. The description enumerates the search criteria (text, resource ID, class name, content description) which aligns with the parameters, but adds no value beyond what the schema already provides for each parameter. Baseline 3 applies since the schema does the heavy lifting.

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 finds UI elements by text, resource ID, class name, or content description and returns coordinates. This is a specific verb+resource combination that adequately communicates the function, though it doesn't explicitly differentiate from siblings like ui_tap_element or ui_get_state beyond implying it returns coordinates.

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 implies usage context (finding UI elements before interacting with them) but doesn't explicitly state when to choose this over siblings like ui_dump, ui_tap_element, or ui_get_state. There's no when-to-use or when-not-to-use guidance, though the nature of returning tap coordinates hints at its role as a preamble to tapping.

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