Launch an isolated Chrome browser session for automation, assigning a unique session ID, debug port, and user data directory.
Launch Chrome browser with session management. Each instance gets a unique session ID, port, and user data directory for isolation.
| Name | Required | Description | Default |
|---|---|---|---|
| debugPort | No | Remote debugging port (auto-assigned per session if not provided) |
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 burden, and it does disclose real behavioral facts: per-instance session IDs, ports, and isolated user data directories. However, it says nothing about failure modes, whether the call blocks until the browser is ready, lifetimes, or the need to clean up sessions.
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?
Two tightly written sentences with the main action front-loaded and no filler. The second sentence adds isolation context that 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?
Adequate for a zero-required-parameter launcher with a fully documented schema, and the mention of session IDs implicitly covers the return value. It is still incomplete on lifecycle: how long the session lives and when to invoke close_browser or cleanup_sessions is left unstated.
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 there is only one optional parameter, so the schema fully documents debugPort including auto-assignment. The description adds no syntax or format detail beyond that, making 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?
States a specific verb and resource ('Launch Chrome browser') plus a distinguishing scope ('with session management'), which separates it from siblings like close_browser and list_sessions. It does not explicitly name an alternative, so it stops short of a 5.
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 explicit guidance on when to launch versus reuse an existing session, nor any note about the relationship to cleanup_sessions or close_browser. Usage is only implied by the tool name and the mention of session IDs.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.