check_login

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

With no annotations, the description carries the full burden of behavioral disclosure. It openly states that the tool may open a browser window for login, and explicitly mentions that it only reports cookie/localStorage key names and never exposes token values. This is thorough and transparent for a tool with side effects.

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 concise and well-structured: the first sentence states the primary purpose, the second describes the side effect, and the third discloses data handling. Every sentence adds meaningful information with no unnecessary words.

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?

The tool has no output schema, so the description should clarify what the tool returns. It mentions 'reports key names' but does not specify whether the return is a boolean, a list, or a structured object. The side effect is described, but the exact output format remains ambiguous, leaving a gap for the agent.

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 tool has zero parameters, and the input schema is empty. According to the rubric, a zero-parameter tool gets a baseline score of 4. No parameter-specific meaning is needed, and the description does not need to compensate for missing schema details.

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's purpose: checks login status for kifrs.com. It also mentions the side effect of opening a browser window if not logged in, which adds scope. No sibling tool has a similar login-related function, so it is well distinguished.

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 usage is implied: one would call this before performing authenticated operations on kifrs.com. However, the description does not explicitly say when to use it, when not to, or mention any alternatives, leaving the guidance implicit rather than direct.

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