set_cookie

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

With no annotations, the description effectively discloses key behavioral traits: it cannot set HTTP-only or cross-origin cookies, and is limited to the current origin. It could be improved by mentioning overwrite behavior, but the provided information is sufficient.

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?

Three sentences with no waste: first sentence states purpose, second adds key limitation, third provides alternative. Front-loaded and efficient.

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's simplicity and presence of an output schema, the description covers purpose, limitations, and alternatives. It could mention what happens if the cookie already exists, but overall it is adequately complete.

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 add meaning. It does not explain what the 'name', 'value', or 'domain' parameters do. The names are somewhat self-explanatory, but the 'domain' parameter's effect (e.g., setting for subdomains) is not clarified.

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 clearly states the tool sets a cookie via document.cookie, with the specific resource (cookie) and verb (Set). It distinguishes from sibling import_cookies by noting the limitation to current origin.

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?

Explicitly states when not to use the tool (HTTP-only or cross-origin cookies) and recommends an alternative tool (import_cookies) for restoring full sessions across origins.

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