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

With no annotations, the description carries the full burden of behavioral disclosure. It only mentions the purpose without any details on side effects, permissions, rate limits, or output behavior. There's no indication whether this is a read-only operation or if it makes external calls.

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 brief, but this is under-specification rather than concise efficiency. Key information about the parameter, usage, and behavior is missing, so the brevity works against clarity.

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?

The description is severely incomplete for an agent to call this tool correctly. It lacks any explanation of the parameter, expected input, return format, or when to use it. The presence of an output schema is not disclosed, and the agent has no idea what data to expect back.

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 input schema has one parameter 'q' with 0% description coverage. The description does not explain what 'q' represents, its format, or its purpose. The default empty string suggests it might be optional, but no semantics are provided.

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 states the resource (ETH Contract) and a vague action ('check') plus a specific feature (Sourcify verified source). It's not a tautology, but it lacks specificity about what 'contract check' entails and doesn't clearly distinguish from sibling tools like ethaddr which likely also deals with Ethereum addresses.

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?

No guidance is provided on when to use this tool versus alternatives. The description gives no context, exclusions, or comparisons to sibling tools.

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