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

Explicitly reconciles the non-obvious readOnlyHint=false annotation: 'Reads or computes only; not marked read-only because each call is charged.' It also discloses the payment model (x402 USDC or card key, first 25 free, failed calls free), which the annotations do not carry. It does not address idempotency or rate limits beyond the free tier, so not a full 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?

Front-loads purpose, then usage, then example, then pricing — a sensible ordering. The paragraph is dense but each clause carries information; the pricing detail is the only part bordering on extraneous for tool selection.

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 carries the burden of describing returns and does so thoroughly, enumerating every field the agent will receive. Combined with the auth/payment disclosure and the worked address example, an agent has everything needed to call it correctly.

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?

Only one parameter with 100% schema description coverage, so the schema already defines it. The description adds a concrete worked example address confirming the expected 0x format, which is marginal added value over the schema — baseline 3 applies.

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 resource (ERC-20 token facts on Base) and enumerates the exact outputs: name, symbol, decimals, supply, owner/renunciation, paused state, proxy detection, and bytecode heuristics. That precision lets an agent distinguish it from price-oriented siblings like price_token, though it never explicitly names an alternative to disambiguate it from contract_risk or token_report.

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?

Gives a clear trigger: 'Use for token due diligence and rug-pull or honeypot screening before a swap.' That is actionable context, but there is no explicit when-not guidance and no named sibling to route to when the agent wants a price rather than risk flags, so it stops short of a 5.

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