Stopping Browser Instance.

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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description adds meaningful context beyond that: the operation permanently closes the browser instance and releases all associated resources, clarifying what gets destroyed. It does not cover auth requirements or error behavior, which keeps it from a 5.

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 zero waste. The core action is front-loaded, and the consequence sentence adds necessary weight without repetition.

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 simple destructive operation with rich annotations and no output schema, the description is nearly complete: it explains what the tool does and what happens to resources. It could still note whether the call fails if no instance is running or what error state to expect, which leaves a small gap.

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 description coverage is 100%, so the schema already documents both profileId and workspaceId. The description refers to the 'specified profile' but adds no syntax, format, or workspace-specific meaning beyond what the schema provides, so the baseline of 3 applies.

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 states a specific verb (stops) and resource (the existing browser instance associated with the specified profile), making the core purpose clear. It implicitly distinguishes from bulk_stop_browser_instance (singular vs bulk) and stop_thread (browser instance vs thread), but does not explicitly name any sibling alternative.

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 description gives no when-to-use or when-not-to-use guidance. It does not mention prerequisites (e.g., the instance must be running), nor does it point to alternatives like bulk_stop_browser_instance for multiple profiles or stop_thread for threads.

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