var

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. The description reveals nothing about how the tool behaves - whether it's read-only or mutative, what data sources it uses, what permissions are required, whether it has rate limits, what format the output takes, or any error conditions. This is completely inadequate for a tool with no annotation coverage.

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 - just three words. While this is efficient, it's arguably too brief given the complexity of VaR calculations and the complete lack of other documentation. However, it does front-load the core purpose 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 this is a financial risk calculation tool with no annotations, 0% schema description coverage, and multiple similar sibling tools, the description is woefully incomplete. While an output schema exists (which might help with return values), the description doesn't explain what data the tool operates on, what methodology it uses, or how it differs from other risk tools. This leaves too many unanswered questions for effective use.

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 description coverage is 0%, meaning the single parameter 'confidence' has no documentation in the schema. The description provides no information about parameters at all - it doesn't mention that confidence is a parameter, what it represents, what range is valid, or how it affects the calculation. For a tool with one undocumented parameter, this represents a significant gap.

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 'Calculates Value at Risk (VaR)' is a tautology that essentially restates the tool name 'var' (which is an abbreviation for VaR). It doesn't specify what resources or data it operates on (e.g., portfolio data, market data), nor does it distinguish this tool from sibling tools like 'portfolio_risk' or 'monte_carlo_simulation' that might also perform risk calculations.

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. There are multiple sibling tools that appear related to risk analysis (portfolio_risk, monte_carlo_simulation, max_drawdown), but the description doesn't explain when this specific VaR calculation is appropriate versus those other tools.

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