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

Goes well past the annotations: it discloses the 422 not_erc20 error for non-token addresses and that such a call is not charged, notes bytes32 symbol decoding, warns that symbol/decimals are contract-supplied and spoofable, gives a latency figure (~1 s), states the USD 0.001 price and the 10 free reads/IP/UTC-day quota, and flags returned on-chain strings as untrusted data. The 'Read-only' line merely restates readOnlyHint=true and is consistent with it.

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?

Purpose is front-loaded in the first sentence and the dense packing of error/cost/limit warnings is efficient. There is mild redundancy — the opening sentence largely repeats the title field, and the chain list is stated twice — which keeps it out of the top band.

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?

Return shape, auth/payment model, error semantics, chain scope and latency are all covered; an output schema exists so return values need not be explained, yet the description still names the key fields. Nothing material an agent needs to call this 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?

Both parameters are fully documented in the schema (100% coverage), including the chain enum and the token address pattern, so the schema carries the burden. The description reinforces the chain restriction but adds no format or semantic detail beyond it — the baseline 3 for high coverage 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 (get ERC-20 total supply) and pins the scope to three named chains. It also explicitly distinguishes itself from the sibling get_token_info, so an agent can route without opening either 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?

"For name and symbol too use get_token_info" names the alternative tool and the condition that selects it. It stops short of a full when-not (e.g. whether to prefer get_balance, get_token_price or scan_contract_address for adjacent needs), so it is clear context rather than complete routing.

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