close_browser

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

With no annotations, the description carries the full behavioral burden, and it does disclose a real consequence: closing discards 'every approval it earned' and 'the grants go with it', plus the cross-session effect on waiting sessions. That is genuine destructive-effect disclosure, but it omits idempotency, behavior when already closed, error conditions, and any auth/permission requirements.

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 action is front-loaded in the opening clause, which is good, but the prose is heavily metaphorical and padded ('discarding every approval it earned', 'name a wait that never ends'). Three sentences do more atmospheric work than informational work.

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?

An output schema exists, so return values need not be explained, and the description does convey the destructive/session-ending nature. But for a terminal, non-annotated tool the safety profile is thin — no note on whether unsaved work is lost, whether double-calling is safe, or what the reason param does — leaving meaningful gaps.

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?

There is one parameter (reason) with 0% schema description coverage, and the description never mentions it at all, so an agent gets no guidance on what the optional reason string is for or how it is used. The description does not compensate for the coverage gap.

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 name and first verb ('Close') clearly signal terminating the browser session, and the description adds lifecycle framing ('this is how a session finishes'). However, it never plainly says it closes the browser/session — it says 'the shared window' and 'approvals it earned', which is metaphorical and forces inference. It also does little to distinguish itself from siblings like open_browser or the takeover tools beyond the closing action.

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 implied rather than stated: 'This is how a session finishes' gestures at end-of-session use, and the closing sentence implies you must call it so other sessions aren't left waiting. There is no explicit when-not-to-use and no named alternative, so the agent must infer the trigger condition.

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