nexus_var_calculator

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

Without annotations, the description must reveal behavioral details. It mentions 'parametric' (implying normal distribution) and 'optional stress test scenarios' but does not specify assumptions, limitations (e.g., linear portfolio), or whether the tool is read-only. No contradictions with annotations (none exist).

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, concise and front-loaded with key outputs (VaR, CVaR, stress tests). No waste, but minimal structure; it could benefit from breaking out optional features.

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 7 parameters and no output schema, the description explains the core computation but lacks details on return format, units, or handling of edge cases. It adequately covers purpose but leaves gaps for an agent to infer behavior.

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%, so each parameter has a description. The tool description adds no extra meaning beyond the schema, e.g., it does not explain how 'confidenceLevel' relates to VaR quantiles. Baseline 3 is appropriate given the schema's completeness.

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 computes parametric Value-at-Risk (VaR), Conditional VaR (CVaR), and optional stress test scenarios, using a specific verb ('Compute') and resource identification. It distinguishes from sibling tools like nexus_rwa_calculator (credit risk) and nexus_analyze (generic analysis) by specifying financial risk metrics.

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 guidance on when to use this tool versus alternatives, such as prerequisites (e.g., need normal distribution assumption) or contrasting with nexus_rwa_calculator for credit risk. It does not mention required input formats or constraints.

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