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

The description fully discloses the paid nature, cost per call, payment mechanism (x402 on Base), and the two-step call process. It also details the return values (fee tiers, costs, congestion). No annotations existed, so the description carries the full burden and meets it admirably.

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 extremely concise: three sentences, each serving a clear purpose. First sentence states the core function and outputs. Second sentence states the cost. Third sentence explains the payment workflow. No redundancy or unnecessary words.

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 sufficiently explains the return values (fee tiers, costs, congestion). It also thoroughly explains the unusual payment mechanism. For a tool with only two optional parameters, this is complete and comprehensive.

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 already provides 100% coverage descriptions for both parameters. The tool description adds critical context: the chain default, that payment_signature is optional but used in a specific two-step process, and the payment workflow. This significantly enhances understanding beyond the schema alone.

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 is a real-time gas price oracle for four specific networks, returning fee tiers, estimated costs, and congestion status. It uses specific verb+resource and distinguishes itself from sibling tools like get_crypto_prices by its specific purpose.

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 explicit guidance on the paid, two-step payment workflow: call without payment_signature first, then retry with signature. However, it does not explicitly compare with siblings or state when not to use this tool.

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