close_browser

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

With no annotations available, the description carries full behavioral disclosure. It states that the session's persistent state is ended, enumerating open tabs, cookies, navigation history, and page state, and confirms that calling it with no active session is safe.

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 compact and front-loaded with the core action. Each sentence provides distinct, useful context: what it does, when to use it, the alternative, and no-session safety.

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 no-parameter lifecycle tool, the description fully covers purpose, timing, state effects, fallback, and edge-case safety. Since an output schema exists, not detailing the return format is acceptable.

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 tool has zero parameters and 100% schema description coverage, so parameter explanation is unnecessary. A baseline of 4 is appropriate because the description does not need to add parameter semantics.

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 opens with a specific verb and resource: 'Close the active browser session and release browser resources.' It also differentiates from sibling start_browser by describing the closure as ending the session and pointing to starting a new session if needed.

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 explicitly says to call this when the browser automation workflow is finished and names start_browser as the alternative for subsequent automation. It also clarifies behavior with no active session, removing ambiguity.

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