get_balance_history

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

Beyond the readOnlyHint annotation, the description discloses important behavioral details: history is monthly, 'With no month range, returns all available history plus an ephemeral `current` entry for the current month, which is calculated on demand and may change between requests', and 'Only months with data are included'. This is rich, valuable context about dynamic data and scope that annotations do not convey. No contradiction with annotations.

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, front-loaded with the primary purpose, and each sentence adds meaningful detail. There is no redundant or filler content. It efficiently conveys scope, data frequency, default behavior, and a caveat about the current month entry.

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 a read-only tool with two optional parameters and no output schema, the description covers the essential information needed for correct invocation: scope (all accounts), frequency (monthly), default range behavior (all history + ephemeral current), and filtering of months with no data. It is sufficiently complete for an agent to select and call this tool correctly.

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?

The input schema covers both parameters (start_month and end_month) with detailed descriptions, including format, inclusivity, and constraints. The description adds only that 'no month range' returns all history, which is already implied by optional parameters. Since schema coverage is 100%, the baseline is 3, and the description does not materially enhance parameter understanding 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 explicitly states 'Get monthly account balance history across all accounts', providing a specific verb, resource, and scope. It also distinguishes from siblings like get_account_balance_history by emphasizing 'across all accounts', and mentions its role as 'the data behind the Net Worth views', adding context. This clearly differentiates it from other balance history tools.

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 clearly implies when to use this tool (for all-account balance history) and explains behavior for no month range. However, it does not explicitly mention alternatives for per-account or crypto-specific balance history, such as get_account_balance_history or get_crypto_synced_balance_history. It provides clear context but no explicit exclusions or alternative recommendations.

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