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

With no annotations, the description carries the burden. It discloses the nature of the data returned (verified-source metadata), including whether the source is verified and proxy/implementation details. It does not mention potential failures or response format, but for a read-only lookup tool, this is adequate.

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 two concise sentences. The first sentence front-loads the core purpose and data items; the second sentence provides the use case. No fluff or 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?

Even without an output schema, the description lists the key return fields (actual name, verification status, compiler, proxy/implementation). It adequately covers the tool's purpose and use case. It could mention error/edge-case behavior (e.g., unverified source), but the stated metadata already includes verification status.

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 50%: the 'chain' parameter is well-described in schema, but 'address' is not. The description adds some meaning by stating the tool is for 'a contract,' implying the address must be a contract address. However, it doesn't elaborate on parameter formats or chain-specific behavior beyond the schema.

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 it retrieves Etherscan verified-source metadata, listing specific data points (actual name, verification status, compiler, proxy/implementation). It also differentiates from siblings by framing the use case as confirming what an address is when onchain reads are insufficient.

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?

Explicitly states when to use: 'Use this to confirm what an address really is when onchain reads alone can't label it.' This gives clear context. It does not name alternative tools or explicitly state when not to use, but the condition is sufficient for most scenarios.

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