Set Session Cookies

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

Annotations already signal idempotency and non-destructiveness, and the description adds the cookie-string format and browser provenance. It does not state whether existing cookies are overwritten or how this affects the session, but the annotations cover the main safety profile.

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?

One concise sentence that front-loads the action and immediately provides the required cookie format. No filler or redundancy.

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 single-parameter setter with idempotence already annotated, the description covers action, resource, parameter format, and provenance. It omits response/persistence details, but those are minor at this complexity level.

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 only provides a minLength string, so the description supplies the essential grammar: 'name1=value1; name2=value2'. This fully compensates for 0% schema description coverage and removes ambiguity about input format.

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?

States a concrete action ('set') on a specific resource ('nexusmods.com cookies') and includes the exact cookie header format. It is clearly distinct from auth-related siblings like web_login or web_status.

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 implies use in a manual flow where the caller provides cookies from a logged-in browser, but it never explicitly says when to prefer this over web_login or when not to use it. No alternatives or exclusions are named.

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