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

With no annotations provided, the description must disclose behavioral traits, but it only points to an external URL and mentions billing per call. It does not describe whether the operation is read-only, what data is returned, or any side effects. The billing note adds some value but is insufficient.

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 very short and front-loaded, but it is under-specified rather than concise. The link and billing info are useful but could be complemented with a clear sentence about functionality. It does not waste words, but it also does not add substantive content.

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 complexity (5 parameters, no annotations, no output schema), the description is incomplete. It relies on an external link and billing note, leaving the agent without information about required parameters, return format, or pagination. This is a minimal viable tool description at best.

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 has five parameters with zero description coverage, so the description must compensate, but it offers no explanations for cursor, userId, proxyUrl, resFormat, or screenName. The external URL might contain parameter details, but that is not accessible to the agent directly. The description adds no value beyond the schema fields.

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 tool name and title clearly indicate it lists a user's followings, but the description is essentially a reference to an external API documentation URL plus a billing note, lacking a plain-language statement of what the tool does. It distinguishes from siblings like followingsIds and followingsListV2 only via the URL's 'friends-list' hint, which may not be sufficient.

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?

There is no guidance on when to use this tool versus alternatives such as followingsListV2 or followingsIds. The description only provides an external link and billing info, offering no context about suitable use cases, prerequisites, or differences from siblings.

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