assets.lookupRead ERC20 token metadata directly from the blockchain using a chain ID and contract address to verify token details.
Read explicit ERC20 contract metadata directly from chain.
| Name | Required | Description | Default |
|---|---|---|---|
| address | Yes | ||
| chain_id | Yes |
Changes observed during successful MCP inspections.
v0.9.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds that data comes 'directly from chain' (on-chain read rather than cache/registry), but does not disclose what happens for non-contract addresses or which metadata fields are returned.
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?
A single, front-loaded sentence with no filler. Every word carries purpose.
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?
Adequate for a simple two-parameter read tool with full safety annotations, but it lacks the metadata fields returned and the behavior for failed lookups, and neither parameter is documented anywhere. It leaves real gaps an agent would want filled.
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 description coverage is 0% and the description provides no parameter meaning at all. The two parameters (address, chain_id) are guessable from their names, but format, expected chain ID conventions, and address validation are undocumented in both schema and description.
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: 'Read ... ERC20 contract metadata', with the qualifier 'directly from chain' adding scope. It is distinguishable in spirit from sibling assets.wrapper_underlying, though neither sibling nor boundary is named.
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?
No when-to-use or when-not-to-use guidance. The word 'explicit' hints that this reads direct contract data rather than derived/wrapper data, but an agent gets no explicit routing versus assets.wrapper_underlying or registry.verify_contract.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.