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

With no annotations, the description carries the burden of behavioral disclosure. It usefully states the cost of $0.001 per call and names the returned fields, and the operation is clearly a read. However, it does not explicitly state read-only behavior, error conditions, or what happens with invalid or unverified contracts.

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 short sentences with no wasted text. The pricing and return-content information are front-loaded and immediately useful.

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?

For a simple three-parameter read tool with full schema coverage, the description is mostly complete: it names the returned metadata and balance and discloses cost. It lacks sibling differentiation and explicit read-only/error behavior, but no critical calling information 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?

Schema description coverage is 100%, so the token, holder, and network parameters are already well documented in the schema. The description adds only broad framing (token metadata and one holder's balance) and does not add syntax, format, or network-selection guidance beyond 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 states a specific resource and output set: ERC-20 token metadata (symbol, name, decimals) plus one holder's balance. This is clear enough to distinguish it from generic chain reads, though it does not explicitly contrast itself with the sibling chain_balance tool.

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?

There is no explicit guidance on when to use this tool versus chain_balance or other chain_* siblings. An agent can infer that this is for ERC-20 token balances rather than native balances, but the description provides no alternatives, prerequisites, or exclusions.

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