Lists all registered interactive hit-test regions on a screen, returning their IDs, positions, and metadata. Omit the screen name to aggregate interactives from every active screen.
List all registered interactive hit-test regions on a screen with their IDs, positions, and metadata
| Name | Required | Description | Default |
|---|---|---|---|
| screen | No | Screen name. If omitted, aggregates interactives from all active screens. |
Changes observed during successful MCP inspections.
v1.15.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It does disclose the return content (IDs, positions, metadata), which is valuable given the absent output schema, but says nothing about read-only safety, ordering, inclusion of hidden/inactive regions, or error 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?
A single front-loaded sentence with no wasted words. It is efficient, though the brevity leaves little room for the usage context an agent would want.
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, optional-parameter, read-only list tool this is close to adequate, and the return-field summary partly compensates for the missing output schema. However, the absence of annotations and any sibling routing leaves meaningful gaps for an agent choosing among the many list_* tools.
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% and the single 'screen' parameter is fully documented in the schema, including the aggregate-from-all-screens fallback. The description adds no syntax or format detail beyond what the schema already provides, so the baseline 3 applies.
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 gives a specific verb ('List') and a precise resource ('registered interactive hit-test regions') plus the returned fields, which is clearly distinct from siblings like list_fonts or list_screens. It does not explicitly name a sibling it is not, so it stops short of the top mark.
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?
There is no guidance on when to call this versus adjacent tools such as find_element_at, inspect_element, or check_overlaps, nor any stated prerequisites. Usage must be inferred entirely from the tool name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.