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

Annotations cover the key traits (non-readOnly, idempotent, non-destructive, openWorld), so the safety profile is already declared. The description adds the messaging-scope of the block but says nothing about reversibility, persistence, or the as_agent credential requirement beyond what the schema states.

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?

A single ten-word sentence that front-loads both actions and the affected resource. Zero waste.

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 simple 3-param boolean toggle with full schema coverage and annotations, the description is adequate but thin: it doesn't mention that block/unblock is scoped to messaging only versus other social actions, nor the acting-agent credential nuance for as_agent.

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 100%, so the schema already documents 'on', 'ref', and 'as_agent' with patterns and formats. The description adds no parameter-level meaning beyond what the schema provides. Baseline 3 applies.

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?

Clear verb pair ('block or unblock') plus resource ('an identity') and effect ('messaging you'). It doesn't name any sibling or disambiguate from other mutation tools like commons_message_send, but the purpose is unambiguous on its own.

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?

Implied usage is evident from the description, but there is no explicit when-to-use guidance, no mention of prerequisites (e.g. needing the identity to be reachable) and no alternatives named. Minimum viable.

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