Close the tab

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

The destructiveHint annotation only flags that something is destroyed; the description specifies exactly what (the owned tab and its daemon) and, crucially, what is spared (the shared browser other sessions may still be driving). That is context annotations cannot convey and it prevents a damaging misread of blast radius.

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 sentences, no filler. The action comes first and the safety boundary second, which is the right order for a destructive operation.

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?

There is no output schema, but for a zero-parameter teardown call there is nothing to return and nothing to configure. The description covers the action, the scope, and the side effect on the shared browser, which is everything an agent needs.

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 takes zero parameters, so there is nothing for the description to disambiguate. Baseline 4 applies; no parameter claims are made or needed.

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 (close the tab, stop its daemon) plus the ownership scope ('this session owns'), which cleanly separates it from sibling session-management tools like browser_open. An agent can pick this without opening any schema.

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?

The sentence 'The browser this session attached to is never closed' implicitly tells the agent when this is appropriate: per-session tab teardown, not full browser shutdown. It doesn't explicitly name an alternative for closing the whole browser, so it stops short of full routing guidance.

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