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

Annotations cover the safety profile (readOnly, idempotent, non-destructive), and the description adds real context beyond them: no API key needed, labels are 'best-effort' (so they may be wrong), flow tags are decoded (to_exchange = sell pressure, mint/burn = supply change), default threshold $1M, and $0.002/call pricing. This is unusually rich behavioral disclosure.

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?

Dense but front-loaded: purpose, data source, payload fields and pricing all land in the first two sentences. The flow-tag glossary is long but each entry carries semantic meaning an agent needs, so the length is defensible rather than padding.

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, so the description carries the return-shape burden and does it: USD size, labels, flow tags, totals by flow, tx links. Combined with cost, default threshold and the alternative-tool pointer, nothing needed to invoke 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 coverage is 67%, and the description compensates by explaining the $1M default threshold and the chain scope ('Base and Ethereum'), which map to min_usd and chains. Only limit (default 25, max 100) is left unexplained by either source.

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 exactly what the tool returns: large USDC/USDT transfers on Base and Ethereum sourced from public explorers, with USD size, exchange labels and flow tags. It also names the sibling it is not (stablecoin_supply), so an agent can distinguish the two without opening a 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?

Gives an explicit use condition ('individual large stablecoin transfers') plus the routing rule for the alternative ('for total supply change use stablecoin_supply'). Coupled with the default threshold and per-call price, an agent knows both when to call it and what it costs.

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