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

With no annotations, the description carries the full burden and does well: it discloses mode-dependence of results and the concrete consequence that a test key omits live-only tokens, naming them. It stops short of stating ordering, whether the list is static/cacheable, or rate limits, which would have made it 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 sentences, front-loaded with the core meaning and followed by the important exception. The field list is dense but every item earns its place; the parenthetical examples of ids help rather than pad.

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?

There is no output schema, and the description compensates by enumerating the returned fields (id, symbol, chain, kind, contract_address, decimals, required_confirmations, min_amount, testnet name, wallet_type). Combined with the test-key caveat, an agent has enough to call and interpret it; only ordering and the chain-filter relationship are unaddressed.

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 chain parameter is fully documented by its enum, so the description adds nothing about filtering. Baseline 3 applies since the schema does all the work and the description never references the chain argument.

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 ('Every asset CoinVello accepts in the API key's mode') and then enumerates exactly what each entry contains. No sibling tool in the list deals with asset discovery, so the scope is unambiguous.

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?

Usage is implied rather than stated: an agent can infer this is the discovery call before creating wallets or checkouts, and the test-vs-live caveat gives useful context. But there is no explicit 'use this when...' routing and no mention of the chain filter as a narrowing option.

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