evm_token_infoName, symbol, decimals and total supply of any ERC20 contract in one call. Useful to label a token address before showing it to a user. Flat $0.001 per call, paid over x402 (USDC).
| Name | Required | Description | Default |
|---|---|---|---|
| chain | No | base | ethereum | polygon | arbitrum | optimism. | |
| token | Yes | ERC20 contract address. |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses the cost ($0.001 per call, paid via x402/USDC) and the output fields (name, symbol, decimals, total supply), which is valuable. However, it does not explicitly state that it is a read-only operation, nor mention potential failure modes (e.g., invalid token address). It is adequate but leaves some behavioral details implicit.
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?
The description is two sentences with no filler. The first sentence states the purpose and output, the second adds the use case and cost. Information is front-loaded and every sentence earns its place.
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?
The tool is simple (2 parameters, no output schema). The description explains what the tool returns (name, symbol, decimals, total supply), covers the use case, and notes the cost. It does not mention error handling or rate limits, but for a straightforward read-only info call, this is sufficient. The lack of an output schema is compensated by listing the fields.
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 100%, so the schema already documents both parameters (chain and token). The description adds a slight clarification that the token is an ERC20 contract address and that the call works for 'any' such contract, but this adds little beyond the schema. The baseline of 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?
The description clearly states the verb and resource: retrieving name, symbol, decimals, and total supply of an ERC20 contract. It is specific and not a tautology. It does not explicitly distinguish from sibling ERC20 tools like evm_erc20_balance or evm_erc20_allowance, but the scope is obvious enough that an agent can infer the difference.
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?
The description provides a concrete use case: 'Useful to label a token address before showing it to a user.' This gives clear context for when to call it. It does not explicitly state when not to use it or name alternative tools, but the use case is sufficiently instructive.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.