x_list_follow_set

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

Beyond the annotations (write, idempotent, non-destructive), the description discloses that the operation is reversible, that the response reports the resulting 'following' state, and that it is disabled under a read-only policy. These are useful behavioral details not inferable from the schema.

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?

Extremely compact: one main sentence delivering the purpose, followed by a short behavioral note and a policy parenthetical. No filler or redundancy; purpose is front-loaded.

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 output schema and annotations already cover return shape, safety, and idempotency, the description adds the remaining key context: target resource, action selection, reversible nature, result reporting, and read-only policy restriction. Nothing essential for correctly invoking this simple two-parameter tool is missing.

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 coverage is 100%: 'action' has an enum with a description, and 'list_id' includes format examples. The tool description does not add parameter-specific meaning beyond what the schema already conveys, so the baseline 3 applies.

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?

States a specific verb ('follow'/'unfollow'), the resource ('a list'), and the acting principal ('as the authenticated user'). This clearly distinguishes it from sibling tools like x_follow_set by the explicit 'list' resource.

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 clear context that this tool is for list follow/unfollow operations, which implies when it should be used. It does not explicitly name alternative tools for user follows or list membership, so it stops short of a 5.

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