create_block

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the action ('Block a user') but doesn't explain what blocking means (e.g., prevents communication, hides content), whether it's reversible, what permissions are required, or what the response looks like. This leaves significant behavioral gaps for a mutation tool.

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 extremely concise and well-structured: a clear purpose statement followed by a bullet-point list of parameters with brief explanations. Every sentence earns its place with zero wasted words.

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 2-parameter mutation tool with no annotations and no output schema, the description adequately covers the basic purpose and parameters but lacks critical behavioral context (e.g., effects of blocking, error conditions, return values). It's minimally viable but has clear gaps.

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?

The description explicitly documents both parameters ('user_id' and 'other_user_id') with clear explanations of their roles, despite 0% schema description coverage. This fully compensates for the schema gap, though it doesn't provide format examples or validation rules, keeping it from a perfect score.

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 clearly states the action ('Block a user') and identifies the resource (user), providing a specific verb+resource combination. However, it doesn't differentiate this tool from its sibling 'delete_block' or explain what 'blocking' entails in this context, preventing a perfect score.

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 provides no guidance on when to use this tool versus alternatives like 'check_block' or 'delete_block', nor does it mention prerequisites or contextual constraints. The agent must infer usage from the tool name alone, which is insufficient.

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