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

Annotations already declare readOnly/idempotent/non-destructive, so the safety bar is lower. The description adds real behavioral context beyond that: the x402 $0.06 per-call pricing, the prepaid x-credit-token header for unlimited calls, the explicit absence of a free tier, and no API key requirement — all material to an agent deciding whether it can afford to call.

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-loads the core question and capability, then covers return shape, input, and pricing in a compact flow. Slightly dense with pricing/header mechanics, but every clause is informative for an agent, so little is wasted.

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-value explanation is not required, yet the description still summarizes the return shape (per-token flags plus wallet-level verdict). Combined with the pricing/auth details, an agent has enough to invoke correctly; only sibling disambiguation is thin.

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% for the single wallet parameter, so the schema already carries the semantics. The description only restates "Required input: wallet" and adds no format, validation, or address-type nuance beyond what the schema provides.

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 ("Scans a wallet's B20 holdings for protocol-level freeze/seize powers") plus the distinctive scope of checking whether the caller's own address is already blocked. It differentiates from generic ERC-20 portfolio tools, but does not name the closest B20 siblings (b20_freeze_check, b20_guard, b20_safety), so an agent cannot fully disambiguate from those.

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 framing ("Built for agents holding Base positions") implies the audience and the risk-check use case, but no explicit when-to-use/when-not or named alternatives are given. The agent must infer that this is the portfolio-level B20 risk scan rather than the single-token freeze check.

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