Account performance history

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

Annotations already cover readOnly, idempotent, and non-destructive behavior. The description adds useful behavioral context: it explains what each report mode returns, notes the default report is summary, and describes the timeseries contents. No contradictions 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?

Three sentences with no filler: purpose first, then the two report modes, then period selection. Every sentence adds distinct necessary information and is front-loaded.

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?

With no output schema, the description gives a reasonable high-level view of what each report returns. However, it doesn't specify behavior when neither standardPeriod nor a date range is provided, nor the interaction rules between those parameters. These are minor gaps for an otherwise clear tool.

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 only 67%, with report and standardPeriod lacking schema-level descriptions. The description compensates by explaining the enum meanings and the choice between standardPeriod and explicit dates. It does not dwell on accountKey/wholeClient, but those already have schema descriptions.

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 'Historical account performance' with explicit verb+resource, and distinguishes two report modes with distinct outputs. It differentiates from siblings like get_account_summary by focusing on historical data rather than current summary.

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 context is implied by 'Historical' and the mention of period selection, but there are no explicit when-to-use or when-not-to-use statements, nor named alternatives. The description never excludes get_account_summary or get_balances, leaving the agent to infer when this tool is preferred.

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