block_user

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

Discloses that X aggressively rate-limits and risk-scans block and mute actions, warning of account restriction for bulk usage. This is useful beyond the input schema, though more details on the effects of blocking could be included.

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?

Concise and well-structured: a clear purpose sentence, a warning note, and parameter description. No unnecessary 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?

Given the tool's simplicity and presence of an output schema, the description covers essential aspects. However, it could mention that blocking is reversible via unblock_user, which is a relevant contextual detail.

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?

Adds crucial format instruction for the screen_name parameter: 'Twitter username (without @)', which is missing from the schema (0% coverage). This fully compensates for the schema gap.

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 'Block a user by screen name', specifying the verb 'block', resource 'user', and method. This distinguishes it from sibling tools like mute_user and unblock_user.

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?

Provides a note about rate-limiting and avoiding bulk usage, which serves as when-not-to-use guidance. However, it does not explicitly compare to alternatives like mute_user.

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