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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description goes beyond these by specifying that both confirmed and unconfirmed balances are returned, that history is optional, and that invalid addresses produce an error with the reason. This adds meaningful behavioral context beyond what annotations provide.

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 convey the primary function, optional behavior, and error case with no wasted words. The main balance result is front-loaded, followed by the conditional transaction history and error handling. 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?

For a read-only, idempotent query tool with an output schema and full parameter documentation, this description is complete. It covers the return value, denomination, optionality of history, and error behavior. Sibling overlap is minimal, and the output schema handles return structure, so nothing an agent needs to invoke this tool correctly 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%, and each parameter is already well documented in the schema, so the baseline is 3. The description adds modest value by clarifying that transaction history is optional (signaling the include_history default) and that the balance is in DOI, but it does not meaningfully expand on the parameters themselves. No compensation is needed for coverage gaps.

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 verb and resource: it returns the balance of a Doichain address in DOI, with confirmed and unconfirmed balances. This clearly distinguishes it from sibling tools like get_block, get_transaction, and lookup_name, which address different resources. The optional transaction history is also mentioned, scoping the tool's full purpose.

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 use case is clear and unambiguous: this is the tool for querying an address's balance, optionally with recent transactions. Although no sibling alternatives are named explicitly, none of the listed siblings overlap with this function, so an agent can identify when to call it. The description does not state exclusions, but the context is strong enough to guide selection.

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