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

Goes well beyond the annotations by disclosing cost ($0.01/call via x402 or card key, first 25 free, failed calls free), that repeated calls are charged, and that a non-ERC-20 address returns 422 uncharged. The only redundancy is restating the read-only/non-destructive profile already in annotations.

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 what is returned and the sibling alternative before the pricing detail. The pricing/free-tier sentence is long and slightly overstuffed, but each clause carries actionable information.

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 compensates by enumerating the returned fields. It also covers error semantics, pricing and the fact that no state is mutated, which is everything an agent needs to call this single-parameter tool correctly.

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 description essentially restates the schema's token parameter (ticker or 0x address). It adds marginal value with a worked example address and the 422 behavior for non-contract input, so baseline 3 is appropriate.

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?

Names a specific verb and resource ('look up the name, symbol, decimals and total supply of an ERC-20 token contract on Sei') and names the output fields, so the agent knows exactly what comes back. It also explicitly separates itself from the close sibling sei_token_balance.

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 two concrete use cases ('identify an unknown token address', 'format raw amounts') and an explicit exclusion routing to sei_token_balance for holder balances. No inference is required to choose between them.

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