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

Annotations only cover readOnlyHint and openWorldHint; the description adds the critical non-schema behavior: a 3-call/day free quota shared across all tools, then $0.024 USDC via x402 or card credits, and the exact in-band payment mechanism (params._meta["x402/payment"]). That payment/quota disclosure is exactly what an agent needs before invoking a metered tool and is unavailable anywhere else.

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 pricing preamble occupies roughly the first third of the text and precedes the actual purpose, so the definition is not front-loaded on what the tool does. The trailing URL plus "built for AI agents on x402" partially restates the payment sentence, adding redundancy.

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 values need not be explained, and the description still gives the verdict scale (low/medium/high). With metering, payment channel, and scan scope all covered, the remaining gap is only edge behavior (e.g., what a partial scan failure or quota exhaustion returns).

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% and both params are documented (address format, optional token contract), so the schema carries the semantics. The description adds only indirect meaning via "per-token risk scoring", which hints at what the optional token param triggers, but does not explain defaults or what happens when token is omitted.

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 ("Full safety scan of any wallet") and enumerates the components: profile and holdings, portfolio value, per-token risk scoring, rug-pull check, plus the output form (one verdict of low/medium/high). The phrase "One call instead of four" explicitly differentiates it from the sibling primitives (wallet_profile, token_portfolio, token_risk, rug_check) that an agent could otherwise chain.

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?

"before you transact" gives a clear trigger condition, and "One call instead of four" tells the agent this replaces a multi-call workflow. It stops short of explicitly naming the sibling tools it supersedes or stating when a single-purpose call would be preferable, so no exclusion guidance.

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