estimate_gas

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

The annotations already declare readOnlyHint=true and destructiveHint=false, covering the non-mutating nature of the tool. The description adds the key behavioral insight 'without sending it', but it does not disclose return format, potential failure modes, or network-dependent behavior. This is acceptable but not thorough.

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 a single nine-word sentence that is direct, front-loaded, and contains no unnecessary wording. It efficiently communicates the tool's core purpose.

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?

There is no output schema, so the description should ideally clarify what the tool returns (e.g., the estimated gas amount and units), but it does not. Additionally, the transaction parameter is a nested object with nine fields and the description gives no guidance on required properties or defaults. The description is sufficient for selecting the tool but not for correctly invoking it without substantial prior domain knowledge.

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 description refers only to 'a transaction' and does not describe any of the fields in the nested transaction object. With schema description coverage at 0%, the agent gets no guidance on which properties are required or how they affect the estimate. The property names in the schema are somewhat self-explanatory, but the description fails to compensate for the lack of schema descriptions.

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 states a specific action ('Estimate gas') and a specific resource ('for a transaction'). The qualifier 'without sending it' clearly distinguishes this from the sibling send_raw_transaction tool, and 'for a transaction' differentiates it from the network-level get_gas_price tool.

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 phrase 'without sending it' implies the tool should be used when a gas estimate is needed before an actual transaction is broadcast, and it excludes the send use case. However, it does not explicitly name alternatives like eth_call or get_gas_price, so it provides clear context but no explicit exclusions.

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