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

Beyond annotations (destructiveHint, idempotentHint), the description adds a crucial warning: 'Records on the old resolver won't be visible after switching. Set up records on the new resolver first.' This transparently discloses the destructive effect and provides mitigation advice, fully satisfying the dimension.

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 concise with a clear structure: summary, conceptual explanation, use cases, special parameter value, and warning. Every sentence serves a purpose, and the most critical info (purpose) is front-loaded. No redundancy.

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 absence of an output schema, the description provides sufficient context for an agent to invoke the tool correctly. It covers what the tool does, when to use it, and behavioral consequences. A minor gap is not describing the return type (e.g., transaction receipt), but the action-oriented context is complete enough for deterministic use.

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?

Input schema covers both parameters with descriptions, but the description adds value by detailing the 'public' shortcut for the resolver parameter, saving the agent from looking up the address. This extra semantic enhancement justifies a score above baseline 3.

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 starts with a clear verb+resource: 'Change the resolver contract for an ENS name.' It explains what a resolver does and lists common use cases, making the purpose unmistakable. While it doesn't explicitly differentiate from siblings, the tool's function is unique enough to be well-understood.

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 explicit when-to-use guidance via common use cases (migrating, custom resolver, fixing no resolver) and mentions using 'public' for the ENS Public Resolver. It lacks explicit when-not-to-use statements, but the context is adequate for correct selection among siblings.

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