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

Annotations already establish readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context by saying it returns holder address and balance and supports an optional snapshot date, but it does not disclose rate limits, error behavior, or authentication requirements beyond the schema. This is adequate but not rich.

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 plus a focused example, with the main behavior stated immediately in the first sentence. There is no filler or repetition of schema content. The example earns its place by showing realistic parameter values.

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 read-only query with a rich schema and no output schema, the description is complete enough: it states the return fields, the optional date filter, and demonstrates a call. It does not specify output ordering or units, but 'top holders' and 'largest balances' sufficiently imply ordering and balance semantics.

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%, with clear descriptions for token, network, limit, date, and _apiKey. The description adds the high-level notion of snapshot scoping and a concrete example, but it does not add meaning beyond what the schema already documents. The baseline of 3 applies because the schema carries the parameter burden.

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: top token holders by largest current balances for an ERC-20 contract on an EVM chain. It also states the returned fields (holder address and balance), making the operation obvious. It does not explicitly contrast with bitquery_dex_trades or bitquery_token_transfers, so it misses the top level of sibling 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 by the purpose: use this when you need the largest token holder balances. The optional snapshot-date behavior gives a small condition, but there is no explicit when-not guidance or mention of alternatives like bitquery_token_transfers. The description does not tell an agent how to route between the Bitquery sibling tools.

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