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

The readOnlyHint already tells the agent this is side-effect free; the description adds the meaningful context that the payload is explanatory reference material rather than fetched data. It also discloses the companion lookup (attest_status + payment nonce) needed to obtain the receipt, batch and Merkle path. It stops short of saying whether the content is static or versioned against the on-chain contract.

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?

Two sentences, front-loaded with the purpose followed by an enumeration of contents and a handoff pointer. The first sentence is dense with a four-item list but every item is substantive; nothing is padding.

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?

An output schema exists, so return format need not be explained, and the description adequately covers the scope of the documentation content plus the follow-up call needed to use it. The only gap is the absence of any disambiguation from the other *_spec tools in this family, which matters given how many siblings share the naming pattern.

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 tool takes zero parameters, so the baseline is 4. The description correctly implies a parameterless reference lookup, and the nonce/nonce-scoped data is attributed to attest_status rather than to this tool, which avoids misleading the agent into passing arguments here.

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 names a specific deliverable: a how-to for verifying a paid-answer receipt, enumerating exactly what it covers (what is hashed, Merkle batching, opBNB calldata layout, verification steps). That is far more concrete than the bare name 'receipt_spec'. It does not, however, distinguish itself from sibling spec tools such as attest_spec or proof_spec, which cover adjacent verification topics.

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?

Usage is implied ('How to verify ... yourself') and the closing sentence points the agent at attest_status with a payment nonce for the actual data, which is a useful routing hint. There is no explicit when-to-use/when-not statement and no indication of how this differs from attest_spec, proof_spec or delivery_spec, so an agent must infer selection.

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