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

With no annotations, the description carries the behavioral burden and discloses several important traits: multicall3 batching, supported chains, a 400 error for non-contract addresses, and a $0.002 x402 price. It does not cover rate limits, partial multicall failures, or response shape, so it is strong but not exhaustive.

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 compact, front-loaded with the core operation, and every sentence adds useful information about scope, errors, or pricing. There is no wasted text.

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 four-parameter read tool with no output schema, the description adequately lists the returned metadata fields and includes important error and pricing context. Minor gaps remain around output structure and request_id behavior, but those are partly covered by the schema.

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 75%, so the baseline is 3. The description adds some mapping for chain and holder balanceOf, but it largely repeats schema-provided meaning and does not explain request_id or idempotency behavior.

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 names a specific verb and resource: read ERC-20 name, symbol, decimals, totalSupply, and optional holder balanceOf. It is clear what the tool does, but it does not explicitly differentiate itself from siblings such as token_price or token_risk.

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 when-to-use or when-not-to-use guidance, and the description does not route the agent away from related siblings like token_price or token_risk. The intended use is inferable from the stated purpose but is not actively guided.

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