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

Beyond the annotations, the description discloses the success payload shape ({ controlMode: "human" }) and that the operation works during a pending approval. It also clarifies that this is not HUMAN_HAS_CONTROL, which adds behavioral context without contradicting the annotations.

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 short and front-loads the core action. The final sentence about HUMAN_HAS_CONTROL is ambiguous and slightly reduces clarity, but otherwise there is little wasted text.

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 one-parameter tool with annotations and no output schema, the description covers purpose and some behavior. However, it leaves the sessionId parameter unexplained and the HUMAN_HAS_CONTROL reference unclear, so it is only minimally 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?

The schema has zero description coverage and the description never mentions sessionId, so it adds no meaning beyond the parameter name. The single required identifier is somewhat self-explanatory, but the description does not compensate for the missing schema documentation.

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 a specific verb and resource: returning control of the tab to the human. It also distinguishes this from HUMAN_HAS_CONTROL, though that phrase is cryptic and no sibling tool is named explicitly.

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 implies when the tool is usable by saying it works while an approval is pending, but it does not state when to prefer it over alternatives such as browser_cancel_approval or browser_get_status. Usage guidance is present but incomplete.

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