reverse-lookup

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

With no annotations provided, the description carries full burden but offers minimal behavioral insight. It doesn't disclose whether this is a read-only operation, if it requires authentication, rate limits, error conditions (e.g., unregistered addresses), or what happens on failure. The description is functional but lacks critical operational details.

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 a single, efficient sentence that directly states the tool's purpose without unnecessary words. It's front-loaded with the core functionality and appropriately sized for a simple lookup operation. Every word earns its place.

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 lookup tool with one parameter and no output schema, the description is minimally adequate. However, without annotations or output information, it doesn't address what the tool returns (e.g., ENS name string, null for unregistered addresses) or error behavior. The description covers the basic 'what' but misses important contextual details.

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 100%, with the single parameter 'address' clearly documented in the schema. The description adds no additional semantic context beyond implying the parameter's purpose. This meets the baseline for high schema coverage, but doesn't enhance understanding of parameter usage or constraints.

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 specific action ('Get') and target resource ('ENS name for an Ethereum address'), distinguishing it from sibling tools like 'resolve-name' (which likely does the opposite) or 'get-name-history' (which provides historical data). It precisely communicates the tool's function without ambiguity.

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. It doesn't mention prerequisites (e.g., address format), exclusions (e.g., invalid addresses), or comparisons to siblings like 'resolve-name' (which might convert ENS names to addresses). Usage context is implied but not explicitly stated.

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