Get Performance

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

With readOnlyHint=true, the annotation already establishes the read-only nature. The description adds that data is historical and includes NAV and time-weighted returns, providing moderate context. It does not disclose return format, pagination, or other behavioral details, so it falls in the mid-range.

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 sentence that is front-loaded with the verb and resource. Every phrase (historical, account performance, NAV, time-weighted returns, configurable period) contributes meaning without waste.

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 two-parameter read tool with full schema coverage and a read-only annotation, the description provides a clear overview. It is adequate for an agent to understand the tool's purpose, though it leaves some usage guidance implicit. No output schema exists, so the description could mention return format, but it's not essential for this simple 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 100% with descriptions for both accountIds and period. The description's mention of 'configurable period' adds no new meaning beyond the schema's enum and description. The accountIds parameter is not elaborated beyond the schema, so the description adds minimal value here.

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 it gets historical account performance with specific metrics (NAV, time-weighted returns) over a configurable period. This distinguishes it from sibling tools like get_pnl or get_account_summary by focusing on performance rather than P&L or summary balances.

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 implies use for historical account performance queries but does not explicitly state when to use this tool over related siblings like get_pnl or get_account_summary. No alternatives or exclusions are mentioned, leaving the agent to infer from context.

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