follow_user

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

Annotations already declare the write/idempotent/open-world profile, so the bar is lower, and the description adds real value beyond them: it discloses that the result is the new is_following state (no output schema exists to carry this) and that repeated calls toggle rather than set, which is exactly why idempotentHint=false. It still says nothing about idempotency-adjacent edge cases like following yourself or rate limits.

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?

Three short sentences, front-loaded with what the tool does and the toggle semantics, with no filler. The 'Required: username' clause mildly duplicates the schema's required array, which is the only small redundancy.

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 one-parameter tool with a full annotation set, the description covers the verb, the toggle semantics, the required input, and the return value (important given no output schema). Nothing an agent needs in order to call it correctly 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 description coverage is 100% and the single parameter is documented in the schema itself ('Haraj username to follow/unfollow'), so the schema does the heavy lifting. The description restates that username is required but adds no format, casing, or identifier-type detail beyond the schema.

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 names a specific verb pair and resource ('Follow (or unfollow) a user'), which is the key detail an agent needs since the operation is a state toggle rather than an absolute set. It does not explicitly name the sibling it is not, such as is_following_user, but the verb+resource pair is unambiguous.

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?

Usage is implied by the verb itself, and the toggle behavior hints at the condition under which it flips state, but there is no explicit guidance on when to call this versus the read-only sibling is_following_user, nor any mention of prerequisites such as authentication or target-user existence.

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