Close a session

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

The description explains the main side effects (freeing context and closing popups) and mentions the idle auto-close mechanism, making the tool's impact on the environment clear. It does not contradict the readOnlyHint false or idempotentHint true annotations, as closing is a mutation and repeated closes are 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 two sentences with no redundant wording. It efficiently conveys the action, the scope, and the automatic behavior.

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?

It covers the essential aspects for a close operation: what is closed, what is freed, and when it might not need to be called. It does not mention error conditions or return values, but those are less critical for this simple tool.

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 sole parameter sessionId is not described in the schema, but the description references 'a session opened with browser_session_open', strongly implying that sessionId is that identifier. This compensates for the missing schema description.

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 tool closes a session and frees its context, directly naming the associated open tool. It distinguishes the action from other session operations without ambiguity.

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 implicitly conveys when to use (after opening a session) and provides the automatic timeout behavior, which helps the agent decide whether explicit closing is needed. It does not explicitly compare with sibling tools, but the context is sufficient.

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