twitter_follow_user

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

Annotations already indicate readOnlyHint=false and destructiveHint=false, so the write nature is known. The description adds important behavioral context beyond those booleans: the action is performed AS the authenticated account and specifically requires write capability. It does not contradict annotations, and mentions the reversible counterpart. Some side-effect detail (e.g., rate limits or failure semantics) is absent, but annotations lower the burden.

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 deliver the core purpose, authentication requirement, and reverse-tool pointer without wasted words. The most critical information is front-loaded in the first sentence.

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 write operation with no output schema, the description covers what it does, how to authenticate, the required format of user_id, and the reverse operation. The schema fully documents all parameters, and annotations cover the safety profile. Minor gaps like expected response or failure behavior are not severe given the tool's simplicity.

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%, so the baseline is 3. The main description adds meaningful guidance for the key user_id parameter ('Resolve a handle to a user_id first with twitter_user_info') and reinforces the auth-token pairing context visible in the schema. This extra semantic hint justifies a 4.

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 uses a specific verb ('Follow') plus a clear resource ('a user AS your authenticated account, by numeric user_id'), making the action unambiguous. It also distinguishes itself from the sibling tool twitter_unfollow_user by explicitly naming the reverse operation.

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 states a key prerequisite ('Requires write capability behind your key') and points to the alternative for reversing the action ('Reverse with twitter_unfollow_user'). It does not exhaustively enumerate when to use this vs. relationship-checking tools, but the context is clear enough for an agent.

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