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

Goes well past the annotations: discloses that it performs a live on-chain history lookup, states the return shape (pass / caution / fail with reasons), and gives pricing and rate-limit terms ($0.01 USDC per call after 25 free calls/day), which an agent needs before invoking a paid endpoint. The only tension is that a live on-chain lookup of arbitrary addresses sits uneasily with openWorldHint=false, but the description is otherwise unusually forthcoming about cost and side effects.

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 decision context ("Before sending crypto") before the detail, then layers checks, return format, and price in four dense sentences with no filler. Every sentence carries information an agent would otherwise have to guess.

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?

No output schema exists, and the description compensates by naming the verdict vocabulary and its structure. With 100% schema coverage on the five parameters, the cost model disclosed, and the checks enumerated, nothing material is missing for correct invocation.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning by explaining what the optional parameters are for: "expected" drives the payee-mismatch check and "known" drives address-poisoning lookalike detection. That connects the two most semantically ambiguous parameters to concrete behaviors rather than restating their types.

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 (checks an address) plus the exact scope: checksum, network match, dead/burn/program addresses, payee mismatch, poisoning lookalikes. The domain (EVM/Solana/Bitcoin payment addresses) is narrow enough that an agent can distinguish it from link_check and payment_check without opening any 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?

"Before sending crypto" gives an explicit triggering moment, which is the key selection signal for this tool. It does not, however, name when to prefer link_check or payment_check instead, so routing between siblings 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.