browser_set_cookies

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. However, 'Set a cookie' only restates the tool's basic action and does not mention side effects (e.g., overwriting existing cookies), persistence, URL matching rules, or any security implications. No additional behavioral information is provided beyond what the tool name implies.

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, but it is under-specified rather than concise. The single sentence 'Set a cookie' does not earn its place because it adds no information beyond the tool name. It is not front-loaded with useful detail; it is simply a minimal restatement.

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 7 parameters, no annotations, and no output schema, the description is severely incomplete. It omits return values, error conditions, behavioral details, and any contextual information about how cookies are set. The description is far too minimal for the complexity of the tool.

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 only 43% (3 out of 7 parameters have descriptions), yet the description provides zero parameter information. It does not mention required fields like 'url', 'name', or 'value', nor does it clarify any of the optional fields. With low schema coverage, the description fails to compensate by explaining parameter semantics.

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 cookie' clearly states the action (setting) and the resource (cookie). It is specific and unambiguous, though it does not explicitly differentiate itself from sibling tools like browser_set_storage or browser_get_cookies. This aligns with a clear purpose without sibling differentiation.

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. There is no mention of prerequisites (e.g., a current page), context for when setting a cookie is appropriate, or exclusion of cases where another tool might be preferred. The user is left without any usage context.

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