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

Annotations only declare readOnlyHint and openWorldHint; the description goes well beyond by disclosing pricing ($0.002 USDC per successful call via x402, failed calls not charged) and the non-error behavior for unverified contracts (verified=false). The read-only claim is consistent with readOnlyHint.

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?

Front-loaded with the core purpose, then error semantics, chains, read-only flag, and pricing, all in a single tight paragraph. The chain enumeration duplicates the schema slightly, which is the only minor 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?

An output schema exists so return values need no expansion, yet the description still summarizes them. It covers chain support, unverified-contract behavior, read-only nature, and the payment model an agent must know before calling.

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% for both parameters, with chain enum values and the 0x address format already documented in the schema. The description repeats the chain list but adds no new syntax or default semantics (default base is already in the schema), so the baseline of 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?

Specific verb+resource: reports whether a contract's source is verified on Sourcify and returns name, compiler, license, and ABI functions/events. This clearly separates it from siblings like evm_token (token metadata), evm_address (address info), and evm_call (RPC calls).

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 scope is implied by the Sourcify verification framing, and the chains list helps pick valid inputs, but the description never states when to choose this over evm_call, evm_token, or evm_decode for ABI-related needs, nor does it give explicit exclusions.

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