i_login_with_cookie

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

With no annotations, the description must carry the behavioral load; it does disclose the hard prerequisite that the cookie must come from an authenticated session and must contain a 'ctoken' entry. It says nothing about failure behavior (invalid/expired cookie), whether the session persists across calls, or whether success is verified, which are the traits an agent most needs for an auth tool.

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?

Two tight sentences; the mechanism and its reliability advantage are front-loaded, and the concrete DevTools path is the kind of practical detail that earns its space. No redundant restatement of the name or title.

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 two-parameter auth tool with no output schema and no annotations, the description covers the prerequisite environment, the source of the credential, and the required token field, which is enough to invoke it correctly. Only the post-login outcome (session persistence, failure signaling) is left unaddressed.

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 100% and already explains both the cookie format and the ctoken fallback, so the description adds no parameter meaning beyond the schema. Its mention of '(or pass ctoken separately)' simply restates the schema's fallback rule.

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 specific verb and resource (log in to iconfont.cn) plus the exact mechanism (raw Cookie header from a logged-in browser). It clearly separates itself from password/SMS siblings by framing cookie auth as the most reliable, headless-friendly route.

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?

Gives clear conditions for choosing this tool: works in headless/CI environments and is the 'MOST reliable method', implicitly steering agents away from i_login_with_password and i_login_with_sms. It does not explicitly name an exclusion case or state what to do if login is already established (i_check_auth), so it stops short of a full when/when-not statement.

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