performance

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals that the tool reconstructs a daily equity curve from the ledger and real historical prices, which gives useful context about the computational method. However, it does not state whether this is a read-only operation, any potential side effects, data requirements, or failure scenarios.

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 with no wasted words. It front-loads the key metrics in a clear list, then provides a concise methodological note. Every sentence earns its place, and the structure is immediately scannable.

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 complexity and the presence of an output schema, the description covers the core purpose and method well. However, with no annotations, no parameter guidance, and no usage alternatives, the description is not fully complete. The single-parameter schema reduces the burden, but the lack of behavioral and selection guidance leaves gaps.

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 has one required parameter 'account' with 0% description coverage, and the tool description does not mention parameters at all. The meaning of 'account' is implied by the tool name and concept of portfolio performance, but no explicit semantics are provided. Since the description adds no parameter-specific value beyond the schema's title, this dimension scores low.

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 tool's purpose as computing portfolio performance metrics since inception, including return, CAGR, Sharpe, Sortino, volatility, and max drawdown. It distinguishes itself from siblings like 'pnl' (simple profit/loss) and 'summary' by specifying risk-adjusted metrics and the equity-curve reconstruction method.

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 explicit guidance on when to use this tool versus alternatives. It does not mention any exclusions, prerequisites, or comparisons to sibling tools such as 'summary', 'pnl', or 'account_details'. The usage context is only implied by the specific metrics listed.

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