util_var

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

The description states the output is the maximum loss percentage but does not disclose the underlying calculation method (e.g., historical or parametric) or assumptions. With no annotations, it provides minimal behavioral context beyond the basic function.

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 extremely concise—one sentence in two parts—with no redundant information. The key terms (VaR, confidence, maximum loss percentage) are 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?

Given the tool has only two parameters and no output schema, the description adequately explains the concept and the output. However, it could be more complete by specifying the calculation method or indicating the output is a single number.

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 parameters. The tool description does not add additional meaning beyond what the schema already provides, so baseline score of 3 is appropriate.

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 Value at Risk (VaR) and defines it as the expected maximum loss percentage at a given confidence. This distinguishes it from sibling utility tools like util_sharpe or util_stddev.

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?

No explicit guidance is given on when to use VaR vs alternative risk metrics. The purpose is implied through the definition, but there are no mentions of when-not-to-use or comparisons with siblings.

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