Inspect panel and toolbar controls so a caller can choose an observed selector.
Inspect panel and toolbar controls so a caller can choose an observed selector.
| Name | Required | Description | Default |
|---|---|---|---|
| target_id | No | Exact Chrome tab target ID from browser_list_tabs. Required for changes. | |
| expected_layout_id | No | Expected saved-layout ID. A mismatch stops the operation before writing. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=false, and destructiveHint=false. The description mainly restates an inspection purpose and adds no behavioral context such as what is returned, whether panels include hidden controls, or how this differs from a full UI snapshot.
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 definition is a single front-loaded sentence with no wasted text. It is compact, though the term 'observed selector' is slightly opaque without further context.
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 read-only inspection tool with no output schema, the description should explain what the caller receives (for example, a list of panels and selectors) and how it relates to sibling inspection tools. Instead it gives only a high-level purpose, leaving return shape and practical usage under-specified.
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 the schema already documents target_id and expected_layout_id. The description adds no parameter meaning beyond the schema, which makes the baseline 3 appropriate.
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 states a specific verb ('Inspect') and resource ('panel and toolbar controls'), plus the downstream goal ('choose an observed selector'). It does not distinguish itself from sibling tools like ui_snapshot, ui_find, or pane_list, so it is clear but lacks sibling differentiation.
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 phrase 'so a caller can choose an observed selector' implies a usage context, but it does not explicitly say when to use this tool versus ui_find, ui_snapshot, ui_list_dialogs, or pane_list. Usage is only implied.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.