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

Goes well beyond the annotations: revert behavior (422 with reason, uncharged), the cost model (x402 USDC or card key, first 25 free, failed calls free), non-idempotency implications ('each call is charged, so repeats are not free'), and the non-mutating guarantee. This is consistent with readOnlyHint=true and idempotentHint=false rather than contradicting them.

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?

Front-loaded with the core verb/resource before parameters, usage, errors, and pricing. It is dense but nearly every sentence carries decision-relevant information; the example address and pricing detail are the only slightly padded elements.

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 still explains what comes back (gas units, gwei, BERA cost), covers the failure mode (422 revert with reason), and discloses the payment requirement. An agent has everything needed to call it correctly and interpret the result.

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%, so the schema already documents all four parameters and the baseline would be 3. The description adds genuine semantic context by clarifying that value is denominated in BERA and that 'from' is needed when the call depends on the sender, which helps an agent decide when to supply it.

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?

States a specific verb and resource ('Estimate the gas a transaction would use'), names the chain and underlying RPC method (eth_estimateGas), and specifies the three units returned (gas, gwei, BERA). It also explicitly distinguishes itself from the sibling bera_gas, which handles gas price only.

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?

Gives concrete triggers ('use before sending a transaction or to price a batch') and an explicit alternative with the condition that selects it ('for the gas price alone use bera_gas'). Nothing about tool selection is left to inference.

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