calculate_sortino_ratio

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

No annotations are provided, so the description carries the full burden. It explains the formula and the concept of downside deviation, but does not disclose any behavioral traits such as input validation, handling of edge cases (e.g., zero downside deviation), or return format. For a simple numeric calculation, this may be sufficient but lacks 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?

The description is concise with two sentences. The first states the formula and purpose, the second provides comparative context. Every sentence adds value without unnecessary words.

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 that there is an output schema (though not shown) and no complex behaviors, the description provides the core information. However, it lacks explanation of potential errors (e.g., division by zero) and does not describe the return value structure. For a simple tool this is adequate but not thorough.

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 schema has 0% description coverage, so the description must compensate. It mentions the three parameters (portfolio_return, risk_free_rate, downside_deviation) by name in the formula, but does not explain their meaning, expected units, or typical ranges. This leaves ambiguity about what values to provide.

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 the Sortino ratio using the formula (Rp - Rf) / Downside Deviation, and distinguishes it from the Sharpe ratio by noting it only penalizes downside volatility. This is a specific verb+resource with clear purpose.

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 context by comparing to Sharpe ratio ('Like Sharpe but only penalizes downside volatility'), helping users decide when to use this tool. However, it does not explicitly state when not to use it or list alternative tools beyond the implicit comparison.

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