api_indexer_lookup_asset_balances

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions 'Get,' implying a read-only operation, but does not specify pagination behavior (beyond parameters like 'limit' and 'nextToken'), rate limits, authentication needs, or error handling. For a tool with 8 parameters and no annotations, this is insufficient to inform an agent adequately.

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 a single, clear sentence: 'Get accounts holding this asset and their balances.' It is front-loaded with the core purpose, has zero wasted words, and is appropriately sized for the tool's complexity. Every part of the sentence earns its place by conveying essential information.

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?

Given the tool's complexity (8 parameters, no output schema, no annotations), the description is incomplete. It lacks details on behavioral traits, usage context, and output format. While the schema covers parameters, the description does not address how results are structured or any operational constraints, making it inadequate for full agent understanding.

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%, meaning all parameters are documented in the input schema. The description does not add any semantic details beyond what the schema provides (e.g., it doesn't explain how 'assetId' relates to assets or how filtering works). With high schema coverage, the baseline score is 3, as the description doesn't compensate but doesn't detract either.

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 states the tool's purpose: 'Get accounts holding this asset and their balances.' It specifies the verb ('Get'), resource ('accounts holding this asset'), and what information is retrieved ('their balances'). However, it does not explicitly differentiate from sibling tools like 'api_indexer_lookup_account_assets' or 'api_indexer_search_for_accounts,' which might have overlapping functionality, so it falls short of a perfect score.

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 description provides no guidance on when to use this tool versus alternatives. With many sibling tools related to assets and accounts (e.g., 'api_indexer_lookup_account_assets,' 'api_indexer_search_for_accounts'), there is no indication of context, prerequisites, or exclusions. This lack of guidance could lead to confusion in tool selection.

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