Click a web element by its reference ID from a prior observation. Pass the page key to ensure the element is still valid and avoid stale interactions.
Click one observed element by its ref. Pass the page_key from browser_observe to refuse a stale ref.
| Name | Required | Description | Default |
|---|---|---|---|
| ref | Yes | ||
| page_key | No |
Changes observed during successful MCP inspections.
v0.2.8Input schema / properties / page_keyAdded value: +{
+ "anyOf": [
+ {
+ "items": {},
+ "type": "array"
+ },
+ {
+ "type": "null"
+ }
+ ],
+ "default": null,
+ "title": "Page Key"
+}v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds a behavioral nuance about stale refs and how page_key addresses that, which goes beyond the annotations. However, it doesn't disclose side effects (e.g., navigation, state changes) or error conditions. Annotations already indicate readOnlyHint=false and destructiveHint=false, so the safety profile is partially covered, but the description adds limited behavioral context.
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 description is two sentences with no fluff, front-loading the action and the key parameter. 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 click tool, the description covers the essentials: what to click and how to avoid stale refs. It doesn't mention return values (no output schema) or failure modes, but given the tool's simplicity and the presence of sibling tools like browser_observe, it's reasonably complete. A mention of when not to use it (e.g., if you need to run JavaScript) would improve it.
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?
The schema provides no descriptions (0% coverage), so the description must compensate. It explains 'ref' as referring to an observed element and clarifies the purpose of 'page_key' (to refuse stale refs). This adds meaningful context beyond the schema, though it doesn't specify formats or types.
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 ('Click one observed element') and the required resource ('by its ref'), with a specific verb and resource. It distinguishes itself from siblings like browser_act by focusing on clicking a specific observed element and referencing browser_observe as the source of the ref.
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?
It gives a hint about when to use the page_key parameter ('Pass the page_key from browser_observe to refuse a stale ref'), but it doesn't explicitly state when to use this tool versus alternatives like browser_act, nor does it provide exclusions or conditions for not using it. The guidance is implied rather than explicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.