browser_close

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

With no annotations, the description carries the full burden of disclosing side effects and behavior. It states that the operation stops the browser/CDP endpoint, but does not disclose consequences such as closing all tabs, invalidating the session, requiring a previously launched browser, or whether the operation is idempotent. The 'Returns: JSON response from the API' line adds little behavioral detail.

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 very short and front-loads the main action. The Args and Returns sections are minimal and each line serves a clear purpose. There is no redundant phrasing or unnecessary examples.

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?

The tool is simple, with one parameter and an output schema, so the description covers the essential invocation details. However, for an agent choosing among many browser and mobile navigation tools, it lacks any mention of side effects or when browser-level close is appropriate versus tab-level or app-level operations. This leaves a noticeable gap.

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 description for serialno (0% coverage), so the description compensates by explaining that serialno is the browser device serial number obtained from list_devices. This is sufficient for the single required parameter, though it could also clarify what happens if the serialno is invalid or stale.

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 ('Stop the browser / CDP endpoint') and identifies the resource, distinguishing it from tab-level operations like browser_tab_close. It is not a tautology and gives the agent a concrete sense of what the tool does. However, it does not explicitly contrast itself with related sibling tools like browser_launch or browser_tab_close_all.

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 use this tool versus alternatives such as browser_tab_close, browser_tab_close_all, or mobile_stop_current_app. The only contextual hint is that serialno comes from list_devices, which is a prerequisite rather than a usage guideline.

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