block_user

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

With no annotations, the description carries the full burden. It usefully discloses that the action is destructive and requires confirm=true, which is essential safety information. However, it does not describe the actual effects of blocking, whether it can be undone, or any side effects. It is minimal but not misleading.

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 one focused sentence with the critical safety condition front-loaded. There is no wasted text. The heavy capitalization and parenthetical style are slightly rough but still efficient.

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 destructive tool with no annotations and no output schema, the description plus schema give enough to attempt a call: provide user_id and set confirm=true. But it omits what blocking does, when it is appropriate, and how to reverse it. The sibling unblock_user hints at reversibility but is not referenced.

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 only 50%; user_id has no schema description. The tool description does not clarify accepted formats or semantics for user_id, and confirm is already described in the schema, so the description adds no new parameter meaning. Low coverage demands more compensation than this.

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 a specific verb and resource: 'Block a user.' It is clearly distinguishable from the sibling tool unblock_user, so an agent knows exactly which action is being invoked without needing to inspect schemas.

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 implies usage: when you want to block a user. However, it does not explicitly state when to prefer block_user over alternatives or mention unblock_user as the reversing operation. The confirm requirement is a precondition, not usage guidance.

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