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

Annotations already declare this is a mutating operation (readOnlyHint=false), so the description adds value with the scope 'current browser context.' However, it does not disclose whether cookies are overwritten or appended, persistence semantics, or potential side effects on subsequent navigation/requests.

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, focused sentence with no filler or redundancy. It is appropriately front-loaded and easy to parse.

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?

Despite the low complexity, the description is under-specified for correct invocation. With no output schema and 0% schema description coverage, the agent lacks critical details about cookie object structure and behavioral semantics, making the description incomplete for reliable use.

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 one required parameter 'cookies' with no descriptions and schema coverage at 0%. The description does not explain the expected shape of cookie objects (e.g., name, value, domain) or how multiple cookies are handled, relying only on the parameter name for meaning.

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 uses the specific verb 'Set' with the resource 'cookies' and scopes it to 'the current browser context.' This clearly states what the tool does and distinguishes it from the sibling 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?

The description provides no guidance on when to use this tool versus alternatives, no prerequisites, and no exclusions. It only states the operation itself, leaving usage context entirely implicit.

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