accessibility_element_at

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It makes the read-only nature clear and states the return contents, but it does not mention edge cases such as invalid coordinates, no element at the position, coordinate system/scaling, or accessibility permission requirements.

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?

Three efficient sentences: the primary action, the return payload, and the practical use case. No redundant information or filler.

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 two-parameter read-only getter with no output schema, the description covers what it does, what it returns, and when it is useful. It lacks edge-case details like no-element or coordinate validity, but those are minor for this tool's complexity.

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% since both x and y parameters are clearly documented as screen coordinates. The description reinforces the coordinate-based purpose but adds no meaning beyond the schema.

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 uses a specific verb and resource: 'Get the UI element at a specific screen coordinate.' It also names the returned data (role, title, value, position, size), which clearly differentiates it from sibling tools like accessibility_tree or ai_find_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 gives a clear context for use: 'identifying what is under the mouse cursor or at a specific screen location.' It does not explicitly name alternatives or state when not to use it, but the intended scenario is concrete and helpful.

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