calculate_jensens_alpha

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

No annotations provided, so description carries full burden. It explains the formula but does not disclose potential traps like division by zero, input constraints, or output format (though output schema exists). Behavior is transparent for a simple calculator, but limited depth.

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?

Two concise sentences: first gives the formula, second explains interpretation. No filler words; essential information is front-loaded and easy to parse.

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?

Tool is a simple calculation with output schema (not shown). Description covers the core purpose and interpretation but omits practical context like expected input ranges, edge cases, or how to interpret the result (e.g., positive alpha indicates skill). Adequate for a knowledgeable user, but leaves gaps for novices.

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 0% (no parameter descriptions), but parameter names (portfolio_return, risk_free_rate, beta, market_return) are self-explanatory and the formula clarifies their roles. The description adds no further detail beyond the formula, so it minimally compensates for missing 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 clearly states the tool calculates Jensen's Alpha via the formula and interprets it as 'excess return over CAPM expectation' and 'measures portfolio manager's skill'. It distinguishes itself from sibling financial performance tools by specifying a unique formula and interpretation.

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 does not explicitly state when to use this tool versus alternatives like Sharpe, Treynor, or Sortino ratios. It implies usage for evaluating portfolio manager skill relative to CAPM, but lacks direct guidance on selection criteria or contexts.

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