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

The description reinforces the readOnlyHint and openWorldHint annotations by stating 'Read-only' and 'No API keys.' It adds meaningful context beyond the annotations: the public RPC source, cost of $0.01 USDC, and the payTo address, which are material to invoking the tool correctly.

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 packs several useful facts into one compact set of sentences: purpose, payment, parameters, return values, read-only nature, and payTo address. It is dense but each clause earns its place, though some details are squeezed together.

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?

With no output schema, the description helpfully mentions return fields and units (gwei fields + suggestedMaxFee). It also covers cost, payment destination, optional chain, and access method. It does not show a full response shape, but it gives enough for an agent to know what to expect and how to invoke the tool.

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 only parameter, chain, is already fully described in the schema as optional and currently limited to base. The description adds 'Optional chain=base,' which aligns with the schema but does not meaningfully extend it, so the baseline of 3 is appropriate.

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 this is a live Base gas oracle returning gasPrice, maxPriorityFee, feeHistory, gwei fields, and suggestedMaxFee. The verb and resource are specific, and the tool is readily distinguishable from the listed siblings, none of which offer gas data.

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?

It gives clear context for invocation: chain is optional and only 'base' is supported, no API keys are needed, and the call is read-only. It also signals the cost requirement upfront. No explicit alternative tool is named, but no sibling appears to provide equivalent functionality.

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