List receivable currencies

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

With no annotations, the description carries the full burden and does disclose meaningful behavior: filtering to wallets that are actually active, the meaning of an empty result (no wallet attached for that family), and the sandbox prerequisite. It omits auth/permission requirements and any pagination or ordering behavior, which keeps it short of 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?

Two tight sentences with the core behavior front-loaded and the empty-list edge case plus testnet prerequisite following. Dense and largely waste-free, though the final clause about attaching a wallet is more setup guidance than tool behavior.

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 does the work of describing the return: a list of currencies each with its blockchain, and the empty-list case. Combined with the testnet/mainnet explanation, an agent has enough to call and interpret this tool; only minor gaps like auth requirements remain.

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% and the single is_test parameter is fully documented in the schema itself (true = testnet family, false = mainnet). The description reinforces testnet semantics only indirectly via the sandbox-payment sentence, adding little beyond the schema, so the 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 verb+resource (list the cryptocurrencies the merchant can receive) and narrows scope precisely: only currencies with an active wallet, each with its blockchain. This is clearly distinguishable from the payment siblings (create_payment, get_payment, list_payments), which operate on payments rather than the merchant's receivable currency set.

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 clear operational context: use it to see what can actually be received, and the note that a testnet wallet must be attached in the cabinet before a sandbox payment can be paid frames the prerequisite flow. No explicit alternative tool or exclusion is named, but with unrelated siblings there is no real ambiguity to resolve.

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