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

Adds substantial context beyond the annotations: pending/unknown hashes return 404 and are uncharged, each call costs $0.01 via x402/card key, first 25 free, failed calls free, and repeats are not free. That pricing-and-retry information is exactly the kind of behavior an agent needs and cannot get from readOnlyHint/openWorldHint. It stops short of describing the receipt's shape beyond field names, but there is no output schema to lean on, so that omission is only minor.

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 purpose and returned fields, then usage, then input, then pricing. Dense and nearly waste-free, though the inline full 66-character example hash and the payment-mechanics clause make it longer than strictly necessary for a one-parameter tool.

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 carries the return-value explanation and does so adequately. Input contract, failure mode, cost model, and sibling boundary are all covered, leaving nothing an agent needs to call it correctly.

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 hash format is already documented; the description repeats it but adds real value with the 404-on-pending behavior and a concrete example hash. That goes beyond a baseline 3 but does not add anything about edge cases like malformed vs. well-formed-but-unknown hashes.

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, names the underlying RPC method (eth_getTransactionReceipt), and enumerates exactly what is returned (status, gas used, effective gas price, MNT fee, log count, contract created). It explicitly distinguishes itself from the closest sibling, mantle_tx, by naming the fields that belong there instead.

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 concrete use case ("confirm a payment or call went through") and routes the agent to the alternative ("for sender, value and calldata use mantle_tx"). The when-not-to-use case is stated explicitly rather than implied.

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