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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, but the description adds critical behavioral context beyond them: pricing ($0.005 USDC per successful call), payment rail (x402 on Solana), and an HTTPS alternative endpoint. These details materially affect invocation and cost decisions.

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 front-loaded with the core purpose and then packs useful metric, pricing, and endpoint details into a compact two-sentence block. It is dense but every clause contributes information, with only minor room for trimming.

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?

Because there is no output schema, the description appropriately enumerates the returned gas metrics (head block age, base fee, percentiles, maxFeePerGas tiers, transfer costs). The main remaining gap is the optional 'chains' parameter semantics, which prevents a perfect completeness score.

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?

There is one optional 'chains' parameter with 0% schema description coverage. The description lists supported chain names (Ethereum, Base, Arbitrum, OP Mainnet, Polygon, BNB Chain), but it does not explain the parameter format, casing, delimiter, or default behavior when omitted, leaving a key semantic gap for a low-coverage schema.

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 opens with a specific verb+resource: 'Live gas tracker' across named chains. It clearly distinguishes gas tracking from siblings like evm_balance, evm_tx_info, and evm_read by enumerating the exact gas metrics it provides.

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?

Usage is implied by 'Live gas tracker' and the listed metrics, so an agent can infer it is for gas estimation across supported chains. However, there is no explicit when-to-use/when-not guidance or comparison to any sibling tool such as evm_read or evm_tx_info.

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