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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, openWorldHint, destructiveHint=false), so the description's job is to add context, and it does: it lists the signal sources checked and describes the returned verdict (allow/caution/block), action, summary and reasons, plus typical latency. It stops short of stating auth requirements or rate limits, which keeps it at a 4 rather than 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?

It leads with the decision question, then the evidence, then the return contract, then usage and the sibling alternative. Every sentence carries load and none are filler, despite the density.

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 no output schema, the description explicitly enumerates the return payload (signed verdict, action, one-sentence summary, reasons), so an agent knows what it will receive. Combined with the explicit chain coverage and the sibling routing, nothing needed to call it correctly is missing.

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 the address field already documents both the 0x and base58 formats, so the schema does the heavy lifting. The description restates the supported chain set, which largely duplicates the enum rather than adding syntax or edge-case semantics.

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 opening question plus the explicit list of what is checked (sanctions, scam labels, EIP-7702 sweepers, poisoning look-alikes, funding source) states a specific verb and resource, and it names the sibling it is not ('For a token you intend to buy, use check_token instead'). An agent can distinguish it from check_token without opening either schema.

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?

It says exactly when to call it ('before a payment or transfer'), enumerates the supported chains, and routes the token case to the alternative tool. Nothing about when-to-use or when-not-to-use is left to inference.

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