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

Annotations already declare readOnlyHint=true and idempotentHint=true, and the description does not contradict them. It adds valuable behavioral context beyond annotations by disclosing the cost ($0.005 USDC), the payment platforms (Base or Solana), and the output format ('JSON-safe typed values'). This helps the agent understand the tool's side effects and constraints.

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, dense sentence that front-loads the cost and purpose. It contains no filler or redundancy, efficiently conveying the core function without extra words. This is an example of good conciseness.

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 tool is relatively simple with two parameters and no output schema. The description covers the purpose and output format but omits parameter semantics, expected data format, and any constraints or edge cases. Since schema coverage is zero and there is no output schema, the description should provide more context for correct invocation, making it incomplete.

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 0%, so the description must explain the two parameters ('types' and 'data'). It does not explicitly define what these mean; only the general context of ABI decoding implies they are type strings and encoded data. With zero schema coverage, this is a significant gap that fails to compensate for the missing information.

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 a specific verb ('decoding') and resource ('Ethereum ABI'), and mentions the output format ('JSON-safe typed values'). It clearly distinguishes from the sibling abi_encode, which does the opposite. The cost mention also adds clarity on the tool's commercial nature.

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 like abi_encode. It does not state conditions, exclusions, or scenarios. The only hint is the tool name, which implies decoding, but no explicit routing to alternatives is provided.

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