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

With no annotations, the description carries the full load and does disclose meaningful traits: ERC-20-only coverage, per-chain look-back ceilings (Arbitrum 1-6, Monad 1-2), the priced x402 payment requirement ($0.01 USDC), and the shape of returned labels including an OFAC flag. It lacks detail on failure modes for malformed addresses and on latency or rate limits, which keeps it from 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?

The description is dense but well front-loaded: trigger clause first, then a labeled Input/Output/Example/Price sequence that maps cleanly onto what an agent needs before calling. The prose is somewhat packed into long clauses, but no sentence is 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?

For a 4-parameter, read-only, no-output-schema tool, the description supplies output field meanings, chain and window limits, a worked example, and cost. The main residual gap is what partial or empty results look like at the tool level (the zero-transfer case is documented only in the schema), which is minor against everything else provided.

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 description coverage is 100%, so the baseline is 3; the description mostly restates what the schema already documents (base as default chain, hours limits, limit as row count). It adds mild reinforcement by tying 'limit' to counterparty rows and enumerating the four supported chains inline, but no new syntax or constraint meaning.

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 concrete verb and resource set — counterparties ranked by ERC-20 transfers, earliest inbound sender, and wallets the same funder also paid — so an agent can immediately separate this from sibling tools like base_wallet_balances or base_token_flows. It also implicitly scopes itself to a single wallet relationship graph rather than balances or token metadata.

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 'Use when an agent must see who an EVM wallet deals with' gives a clear triggering condition, and the chain/hours constraints tell the agent whether a given request is servable. It stops short of naming alternatives (e.g. base_wallet_balances for holdings, sanctions_address for dedicated OFAC screening), so no explicit when-not guidance is present.

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