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

Annotations already indicate readOnlyHint: true, and the description aligns with that. Adds behavioral context about pagination ('Paginates via cursor') and mentions that full profile metadata is returned, going slightly beyond the annotation.

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 concise sentences: first states the action, second gives the use case. No unnecessary words, front-loaded with the core 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?

Mentions pagination and profile metadata, giving a sense of the response. Lacks details on error cases or exact response structure, but for a simple read tool with readOnlyHint, it is fairly complete.

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 covers all parameters (userName, cursor, pageSize) with descriptions, so coverage is 100%. The description does not add extra clarification for parameters beyond the schema, so baseline of 3 is appropriate.

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?

Clearly states the action ('Fetch') and resource ('the accounts a Twitter/X user follows'), and distinguishes from siblings like get_user_followers by focusing on followings. Includes pagination detail and a use case.

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?

Provides a clear use case ('map a user's interest graph') and implies when to use it (when you need followings, not followers). Does not explicitly contrast with alternative tools, but the purpose is unambiguous.

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