read_contract

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

Annotations already mark it as read-only, non-destructive, idempotent, and open world. The description adds rich behavioral details: proxies are followed once, it refuses unverified contracts with no fallback, validates args via viem, and refuses non-view/pure functions. No contradiction with annotations.

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 well-structured and front-loaded with purpose and constraints. Each sentence adds value, though it is fairly long. Could be slightly trimmed without losing 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?

Given no output schema, the description covers all essential aspects: return format (viem encoder results), edge cases (unverified contracts, proxies, overloads), and argument type validation. It is fully complete for a tool that calls arbitrary view functions.

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 coverage is 80%, but the description provides extensive meaning for each parameter: chain enum listed, contract requires verification or inline ABI, fn disambiguation via full signature, args types with examples (uint256 as decimal string, bytes32 as 0x-prefixed hex, etc.), and ABI override. This far exceeds the schema's descriptions.

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 explicitly states it calls any view/pure function on any verified-ABI EVM contract, mirrors Etherscan's Read Contract, and is the counterpart of prepare_custom_call for writes. It includes specific examples (OZ roles, governance, etc.), clearly differentiating from sibling tools.

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 advises using this tool for the long tail of on-chain reads not covered by protocol-specific tools, and explicitly directs to prepare_custom_call for writes. It also notes that it refuses state-changing functions, providing clear when-to-use and when-not-to-use guidance.

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