Close an owned browser target

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

Annotations already mark this as destructive, but the description adds meaningful behavioral detail beyond that: only owned targets are eligible, unresolved targets need a special flag, and CDP pages are preserved. These are concrete, non-obvious behaviors that help an agent use the tool safely.

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 with no filler. The core action is front-loaded, and the second sentence packs two important edge cases. Every word earns its place.

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?

The description covers the necessary behavioral conditions: ownership, unresolved-target handling, and CDP preservation. However, with no output schema and limited parameter detail, timeout semantics and non-owned target behavior are left unspecified. For a simple three-parameter destructive tool, this is still mostly complete.

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 0%, so the description must compensate. It explains discard_reconciliation behaviorally ('unresolved targets require...'), but it does not clarify timeout_ms or target_id beyond their names and schema constraints. The most important parameter is addressed, but not all.

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 opens with a specific verb and resource: 'Close an owned page.' It clearly states the action, the scope of what can be closed ('owned'), and distinguishes this tool from siblings like list_targets and open_url without requiring schema inspection.

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 clear context for using the tool and a conditional usage rule: 'Unresolved targets require discard_reconciliation=true.' It does not explicitly name alternatives or state when not to use it, but closing is a unique action among the siblings, so the guidance is adequate though not exhaustive.

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