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

With no annotations, the description must carry the full burden. It discloses that coordinates are in physical pixels and can be used directly with device_tap, which is valuable. However, it does not cover failure modes (e.g., element not found, multiple matches) or any side effects, which are important for a tool with no annotation coverage.

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 sentences, front-loaded with the purpose, then the output format and usage note. No redundant information or fluff; every word 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?

For a simple find operation with no output schema or annotations, the description covers the core purpose, output format, and a direct use case. Missing details like behavior when multiple elements match or error handling are minor gaps but not critical for basic invocation.

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 100%, so each parameter is already documented. The description adds clarity about text and contentDesc as primary search criteria, but does not mention resourceId, which could cause confusion. Since the schema handles most semantics, the description provides marginal extra value.

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 action (find a UI element), the resource (Android device), and the criteria (visible text or content description). It also specifies the return value (center coordinates) and how to use it, distinguishing it from sibling tools like device_tap_by_text or device_wait_for_element.

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 a usage pattern by suggesting use with device_tap, but it does not explicitly mention when to choose this over alternatives like device_tap_by_text or device_wait_for_element. The guidance is helpful but not comprehensive, leaving the agent to infer the boundaries.

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