Close the browser connection and clean up session data to end automation cleanly. Optionally target a specific session ID, or omit it to close the current session.
Gracefully close the browser connection and clean up session data
| Name | Required | Description | Default |
|---|---|---|---|
| sessionId | No | Session ID to close (optional, closes current session if not specified) |
Changes observed during successful MCP inspections.
v1.3.8Does 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 two meaningful traits: the close is 'graceful' and it destroys session data, which is useful. However, it omits whether cleanup is reversible, what happens with an invalid or already-closed session, and whether other sessions are unaffected.
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?
One sentence, front-loaded with the action and resource, with no filler. Every clause ('gracefully', 'clean up session data') carries information.
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 zero-required-param teardown tool with no output schema, the description covers purpose, scope, and the cleanup side effect adequately. It could go further on sibling disambiguation and post-close state, but nothing essential to a correct call is missing.
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 optional sessionId already documents its default behavior. The description adds no syntax or semantics beyond the schema, 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?
States a specific verb ('close') and resource ('browser connection'), plus the side effect of cleaning up session data. It is distinguishable from close_all_browsers by scope ('the browser connection' vs. all), but the description never explicitly contrasts the two siblings.
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?
Usage is only implied by the name and scope. There is no explicit guidance on when to use this versus close_all_browsers or cleanup_sessions, nor any note about calling it at end of a workflow.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.