x_follow_set

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

Beyond the annotations, the description discloses that this is a reversible write, that the result reports the resulting `following` state, and that `pending_follow` appears when the target is protected and approval is required. It also notes the policy-based read-only disablement, which is useful operational context not present in the annotations.

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 compact and front-loaded with the primary purpose, then expands into input formats, behavioral output, and policy context without redundancy. Every sentence contributes operational value, and no filler or vague language is present.

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 two-parameter write operation, the description is complete: it covers input semantics, target resolution, action selection, output state, edge case behavior for protected accounts, reversibility, and the read-only policy guardrail. Combined with the existing annotations and output schema, an agent has enough information to select and invoke the tool correctly.

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 already covers both parameters with descriptions and 100% coverage, so the baseline is 3. The description adds meaningful semantics by enumerating accepted `user` formats (numeric id, handle, @handle, profile URL), explicitly stating 'no batch' for a single target, and clarifying that `action` selects between `follow` and `unfollow`.

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 the exact action ('follow or unfollow a user') and the resource ('social-graph write' on X/Twitter), and distinguishes itself from sibling set tools by scoping to the follow relationship. It also clarifies that it handles a single target and is not a batch operation, which separates it from any list or media operations.

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 clear context for when to use the tool: when the authenticated user needs to follow or unfollow a single X user, with supported input formats explicitly listed. It does not explicitly name sibling alternatives or state when not to use it, but the purpose and no-batch constraint make the intended usage clear.

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