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

Annotations only cover the safety profile (readOnly, idempotent, non-destructive), but the description goes well beyond: it explains the no-receipt case returns possible reasons (pending/dropped/never existed) instead of erroring, notes contract deployments report the new address, and discloses the full pricing/auth model ($0.002/call via x402, prepaid x-credit-token header, 1 free call/day, no API key). That is actionable context an agent cannot infer from annotations.

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 outcome questions before the field enumeration, and each sentence carries information. The pricing/credit paragraph is somewhat boilerplate-heavy, which keeps it from a perfect score, but nothing is redundant with the schema.

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 an output schema present, the description needn't explain return shapes, yet it still previews the key fields. Combined with the pending/dropped semantics and the payment requirements, an agent has everything needed to decide, afford, and invoke the call 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?

There is a single parameter with 100% schema description coverage, so the schema already carries the meaning. The description's 'Required input: hash' adds only confirmation that it is mandatory, matching the baseline 3 for a fully documented single-param tool.

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?

Names a specific verb+resource ('The receipt for a Base transaction') and enumerates exactly what the agent gets back: success/reverted, block, gas used, effective gas price, fee in wei and ETH, log count, emitting contracts, and deployment address. It is clearly differentiated from siblings like base_tx or tx_decode by framing the receipt view of a transaction.

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 opening triad 'Did it succeed, what did it cost, what did it touch' tells the agent precisely which question this tool answers, and it states the required input (hash). However, it names no alternative tool and gives no explicit when-not guidance against base_tx, tx_decode, or receipt_parse.

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