compute_portfolio_var

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

With no annotations, the description carries the full behavioral burden. It says it 'Computes' the metrics, implying a read-only calculation, but does not disclose the VaR methodology (parametric, historical, Monte Carlo), distributional assumptions, determinism, or computational cost—all material for interpreting a risk number.

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?

A single front-loaded sentence with no filler. Every clause (regulatory, VaR and CVaR, market risk, holding periods, confidence intervals) contributes useful scoping information.

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?

Inputs are fully covered by the schema, and the description names the two conceptual outputs (VaR and CVaR). However, with no output schema and no annotations, it omits output structure and modeling assumptions, leaving the agent able to invoke it but not fully informed about what it returns.

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 description coverage is 100%, so the schema already documents all four parameters with defaults and examples. The description echoes 'holding periods and confidence intervals' (matching horizon_days and confidence_level) but adds no syntax, constraints, or semantics beyond what the schema provides, so baseline 3 applies.

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 names a specific verb (Computes) and specific resources (Value-at-Risk and Expected Shortfall/CVaR) scoped to market risk, holding periods, and confidence intervals. This clearly distinguishes it from the sibling tools calculate_sacr_exposure, simulate_monte_carlo_pfe, and calculate_portfolio_greeks, which produce different 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 'regulatory' and 'market risk' framing implies the use case, but there is no explicit statement of when to prefer this tool over the sibling risk calculators, nor any exclusions or prerequisites. Usage is inferable but not guided.

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