check_login_status

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

With no annotations, the description carries the full burden and does well: it specifies the return shape (dict with 'logged_in' boolean), which clearly tells the agent what to expect. The verb 'check' implies a read-only, non-destructive operation. It does not mention edge cases or error behavior, but for a simple session status check this level of disclosure is adequate.

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 two short sentences: the first states the core purpose, and the second defines the return format. It is front-loaded, free of filler, and every word serves a purpose.

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 tool with no parameters and an output schema already present, the description fully covers what the tool does and what it returns. The simplicity of the operation means nothing important is missing. The distinction from sibling tools is obvious from the purpose statement.

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 input schema is an empty object, meaning the tool accepts zero parameters. The baseline for zero parameters is 4, and the description correctly avoids mentioning any parameters because there are none. No additional semantic information is needed.

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 states a specific action (check), a specific resource (current Douyin session login status), and is clearly distinct from sibling tools that retrieve content or user data. An agent can immediately understand what this tool does and that it is an authentication status check.

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 gives no explicit guidance on when to use this tool versus an alternative. However, the tool's purpose is unique among siblings and the intended usage (checking whether the session is logged in) is implied by the description. There are no alternatives for this function, so explicit routing is unnecessary.

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