browser_set_cookie

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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It only states the basic action without mentioning side effects (e.g., overwriting existing cookies), security implications, or whether the session must be valid. This is insufficient for an agent to understand the tool's behavior.

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 short sentence), but lacks any structure such as bullet points, examples, or notes. While brevity is valued, it sacrifices clarity and completeness. It earns a middle score.

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 tool is simple, but the description omits important context: it does not mention that a valid session_id is required, what happens on success/failure, or relationships with other cookie tools. An output schema exists but is not referenced. The description is incomplete for an agent to use effectively.

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?

Input schema coverage is 100%, so the schema already documents all 8 parameters with descriptions. The description adds no extra meaning beyond the schema. Baseline 3 is appropriate given the high coverage.

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 browser cookie' clearly states the action and resource. It distinguishes from sibling tools like browser_get_cookies and browser_delete_cookies by specifying 'set'. However, it lacks additional context that could further clarify the tool's role.

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 on when to use this tool versus alternatives, such as when a cookie already exists (it will be overwritten) or prerequisites like having an active browser session. The description 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.