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

With no annotations provided, the description carries the full burden. It explicitly states the call is read-only (eth_call) and mentions the flat $0.001 per call paid via x402, providing transparency about cost and side-effect safety.

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, efficient sentence with no redundant wording. It packs essential information (read-only, raw, no API key/rate limit, pricing) without any fluff.

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?

Despite lacking an output schema, the description states the return type is the raw result, which is sufficient. It explains pricing, usage context, and the tool's role among siblings, making it complete for an agent to select and call correctly.

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 schema descriptions cover all parameters (to, data, from, block, chain) with clear explanations. The description adds the context of 'raw result' but does not materially enhance parameter semantics beyond what the schema already provides, warranting the baseline of 3.

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 the tool 'runs any read-only contract call (eth_call) with your own calldata and returns the raw result.' This is a specific verb and resource, and it distinguishes itself from the many typed EVM sibling tools by being the generic raw call option.

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 phrase 'The escape hatch for anything the typed endpoints do not cover' gives explicit guidance on when to use this tool: when no more specific sibling tool applies. It also notes there is no API key or rate limit, which is useful operational context.

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