close_instance

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

With no annotations, the description carries the full burden. It discloses that closing frees profile and memory, indicating a destructive side effect. However, it omits details about irreversibility, error conditions, or required permissions.

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 extremely concise—one sentence plus a parenthetical note. It front-loads the core action, and every word earns its place without redundancy.

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?

Given the tool has one parameter and an output schema (not documented), the description is too brief. It lacks information about return value, error handling, and prerequisites (e.g., instance must be open). For a simple tool, this is a significant 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 coverage for parameters is 0%, so the description must compensate. The phrase 'specific browser instance' weakly implies the parameter identifies the instance, but it adds no detail about the expected format, validation, or behavior if the ID is invalid.

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 uses a specific verb ('Close') and resource ('a specific browser instance'), making the action unmistakable. It distinguishes from siblings like 'close_all_instances' by emphasizing 'specific', implying the need for an instance identifier.

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 provides no guidance on when to use this tool versus alternatives such as 'browser_close' or 'close_all_instances'. It does not mention prerequisites (e.g., instance must exist) or exclusions.

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