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

Adds substantial context beyond the annotations: fixed gas-unit assumptions (100k/250k/180k), exact priority-fee multipliers per preset, HTTP 400-without-charge on invalid input, and a $0.04 USDC x402 cost per successful call. The readOnlyHint=false is consistent with a charged remote call, not a contradiction.

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?

Dense and front-loaded: purpose first, then assumptions, validity, exclusions, and cost. Every sentence carries distinct information with no filler.

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?

No output schema exists, yet the description covers pricing, invalid-input behavior, estimation assumptions, and scope limits. For a single-parameter tool, nothing an agent needs to call it correctly is missing.

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 already 100%, but the description adds real meaning the enum alone lacks by defining each preset ('high-mev' = 3x priority fee, 'low-gas' = half). This is beyond a baseline 3 because it explains the numeric effect of each option.

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 ('Estimates Base gas costs from current fees and priority-fee presets') and, despite the name mev_simulator, explicitly disclaims simulation/MEV measurement. It does not, however, distinguish itself from the sibling base_gas, leaving one ambiguity for the agent.

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 a clear use case ('Use to budget gas for a Base transaction') and declares when it is not applicable ('No transaction simulation, mempool observation, or MEV/sandwich-risk measurement'). No alternative sibling is named, so routing versus base_gas 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.