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

Discloses behavior well beyond the annotations: the first invocation is non-committal and only returns a confirm_token, and the actual unfollow requires a human-approved second call. This is genuinely useful since destructiveHint=false and idempotentHint=true alone would not tell an agent that a confirmation handshake is mandatory. It doesn't clarify what happens to the confirmation token on expiry or what the preview contains.

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 tight sentences with zero filler: the action is front-loaded and the protocol follows immediately. Every clause carries load-bearing information about the call sequence.

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?

With no output schema, the description correctly explains the one return value an agent must handle (confirm_token) and the required follow-up call. The only gap is that it never says which of userId/username must be supplied on the first call, leaving that to the schema.

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 userId, username and confirm_token are already documented, including the "omit on first call" rule the description restates. The description adds only the ordering of the two calls, so the 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?

States a specific verb+resource ("Stop following someone") that is unambiguous and clearly the inverse of the sibling follow_user, so an agent can tell the two apart without opening schemas. It does not, however, explicitly name the sibling or scope (e.g. by id vs handle) beyond what the params imply.

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?

Gives clear operational guidance for the two-step protocol: call once with no confirm_token to preview, show the preview to the user, then call again with the token only after agreement. There is no explicit when-not-to-use guidance or reference to the follow_user alternative, which keeps it 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.