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

Goes well beyond the annotations: discloses that an unknown hash returns 404 and is uncharged, that failed calls are free, that successful calls cost $0.01 via x402 USDC or a card key, and that repeats are charged. This is genuinely useful pre-call knowledge that annotations cannot express. It stops short of describing the response payload shape or any rate limits, keeping it below a 5.

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 verb and returned fields, then routing, then input format and error behavior. Dense but almost every clause carries information. The pricing sentence is long and stacks several facts (per-call price, payment rails, free tier, failed-call refund), which slightly dilutes the tightness of the rest.

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 single-parameter read tool with full schema coverage and no output schema, everything an agent needs is present: scope, sibling disambiguation, input format with example, and cost/error behavior. There is no meaningful gap left to fill.

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%, so baseline is 3, but the description adds value by spelling out the 0x-prefixed 64-hex format, giving a concrete example hash, and defining the failure semantics for an unmatched hash (404, uncharged). The example makes the format unambiguous without opening the schema.

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 ('Look up a Linea transaction by hash') and enumerates exactly which fields come back: sender, recipient, value, nonce, gas limit, selector, block. It also differentiates itself from the two nearest siblings, linea_receipt and linea_logs, by scope rather than by name alone.

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 explicit routing rules: use this to see what was sent or whether a tx exists, use linea_receipt for success/failure and fees, use linea_logs for emitted events. That is a when-to-use plus two named alternatives with their selection conditions.

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