set_cookie

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. The description consists solely of a code example and reveals nothing about side effects, persistence, scope, whether cookies are session or permanent, or what happens on error. For a tool that mutates browser state, this is a significant transparency gap.

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?

Extremely short (a single line), so it is not verbose, and the example is front-loaded. However, it is under-specified rather than genuinely concise - it substitutes a code sample for an actual description, sacrificing explanatory value for brevity.

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 5-parameter tool with 0% schema coverage, no annotations, and no output schema, the description is grossly inadequate. The code example conveys only a fraction of the tool's behavior, leaving the agent to guess about parameters, return values, error cases, and interaction with browser state. There is no explanation of cookie storage semantics or how this ties into the broader browser-control toolset.

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 for explaining the 5 parameters. The example demonstrates 'name', 'value', and 'domain' usage, but does not mention 'url' or 'path'. It adds no formatting, constraints, or interaction semantics beyond what the schema field names already imply.

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 is just a code example ('set_cookie("token", "abc", domain=".example.com")') rather than a prose statement of what the tool does. It implies the tool sets a cookie, but this is only inferred from the name and example, not explicitly stated. It does not distinguish from related siblings like get_cookies.

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. The example shows a use case but there is no explanation of when setting a cookie is appropriate, prerequisites, or when get_cookies or other tools should be used instead.

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