user_action

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

Annotations declare openWorldHint=true and idempotentHint=true, so the external-call and repeat-safety profile is already given. The description adds a genuine behavioral caveat that block may be refused on pay-per-use apps, which is valuable. However, it does not disclose permissions, reversibility of block/mute, or what happens to an already-followed user.

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 tightly written sentences: the operation list is front-loaded and the Enterprise caveat follows as a scoped qualifier. No filler or redundancy; every clause earns its place.

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 mutation tool with no output schema and only partial annotation coverage (no readOnly/destructive hints), the description is adequate but leaves real gaps: it doesn't say the action requires an authorized account beyond the schema hint, doesn't describe failure behavior for non-Enterprise block, and doesn't cover the remaining parameter documentation gap.

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 67% and the schema already documents both 'user' and 'account' and enforces the action enum. The description's Enterprise caveat adds meaning for the 'block' enum value and 'as the given account' reinforces the account param, but it stops short of compensating for the remaining undocumented parameter detail.

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 the resource (user) and enumerates the exact operations (follow, unfollow, mute, unmute, block, unblock), so an agent immediately knows it is a user-relationship mutation tool. It doesn't explicitly contrast with siblings like post_action or list_action, but the resource scope is clear enough to disambiguate.

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 Enterprise-only note about block is a useful bring-your-own-conditions caveat, but there is no explicit guidance on when to use this vs. related siblings (e.g., get_user_relations) or prerequisites beyond the schema's account param. Usage is implied by the action list rather than stated.

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