Native balance (all supported chains) and ERC-20 token balances (chains with a data-capable upstream) for an address. Chains: e.g. eth_mainnet, base_mainnet, arbitrum_one, optimism_mainnet, polygon_pos, solana_mainnet.
| Name | Required | Description | Default |
|---|---|---|---|
| chain | Yes | Chain slug, e.g. 'eth_mainnet' | |
| address | Yes | Account address (0x… for EVM, base58 for Solana) |
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?
There are no annotations, so the description carries the behavioral burden. It does disclose a useful caveat: ERC-20 balances are only returned on chains with a data-capable upstream, and it gives concrete chain examples. It does not mention response shape, pagination, or explicit read-only behavior.
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 with no filler. The first states the core behavior and scope, while the second gives concrete chain examples. 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 description is sufficient for selecting and invoking the tool with two required parameters, and the caveat about ERC-20 support is useful. However, since there is no output schema, the description does not reveal the return shape or how unsupported chains are represented in the result.
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 baseline is 3. The description adds meaningful value by providing several valid chain slugs and conveying that all supported chains are accepted, which is especially useful since chain has no enum in the schema.
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 identifies the resource: native and ERC-20 token balances for an address, so an agent can infer this is about balances rather than prices or history. It does not explicitly name or contrast sibling tools, so it misses the strongest form of differentiation.
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: an agent needing address balances should call this tool. However, the description does not explicitly say when not to use it or point to alternatives like get_token_prices, get_history, or get_gas_prices.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.