browser_set_cookie

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

With no annotations present, the description carries the full burden of behavioral disclosure. It only states the basic action without revealing important traits such as whether setting a cookie overwrites existing ones, what domain/path it applies to, or if it requires session context. The mutation nature is implied but side effects are not explained.

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 a single, concise sentence that is front-loaded with the action. Every word earns its place, and it is appropriately sized for a tool with this simplicity. No 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 setter tool, the description is minimally adequate, but it omits important context like the role of sessionId, whether a browser session must be active, and how this interacts with the current page. Given the sibling list includes navigation and cookie-related tools, slightly more context would help the agent correctly sequence operations.

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 is 100%, with all parameters (name, value, sessionId) described in the input schema. The description adds no additional meaning or context about parameters, so it does not improve beyond the schema baseline. It neither compensates nor degrades.

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 'Set a single cookie' uses a specific verb (Set) and resource (a single cookie), clearly distinguishing it from sibling tools like browser_get_cookies and browser_clear_cookies. It states exactly what the tool does without ambiguity.

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?

No guidance is provided on when to use this tool versus alternatives. The description does not mention any prerequisites, such as needing an active browser session or navigating to a page, nor does it explain when to prefer this over clearing cookies or getting cookies. It offers no usage context.

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