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

With no annotations, the description carries full burden. It discloses that data is fresh within 15 seconds, returns JSON, and costs $0.002 USDC per call via x402. This is good behavioral context, though further details like rate limits or failure modes are absent.

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?

Two sentences plus a bracketed cost note convey purpose, freshness, output format, and payment. Every sentence is informative and front-loaded, with no waste.

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?

For a simple single-parameter tool with no output schema, the description covers purpose, freshness, output type (JSON), and cost. It is sufficiently complete, though an example or note on units (e.g., Gwei) could further aid.

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 coverage is 100% with a single enum parameter 'chain' already described. The description adds no additional semantic detail beyond confirming the chains (Base, Ethereum). 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 explicitly states the tool retrieves current gas price and latest block for Base or Ethereum mainnet. It uses specific verbs and resources, clearly differentiating from sibling tools which are mostly unrelated.

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 implies usage for querying gas prices and blocks from public RPC with freshness guarantees, but provides no explicit guidance on when to avoid this tool or mention alternatives. Usage context is implied but not formally structured.

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