calculate_mirr

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. While 'Calculate' implies a computational operation, it doesn't specify whether this is a read-only calculation, what format the output takes (e.g., percentage, decimal), error conditions, or performance characteristics. For a financial calculation tool with zero annotation coverage, this is a significant gap.

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, efficient phrase with zero waste. It's appropriately sized for a straightforward calculation tool and front-loads the core purpose without unnecessary elaboration.

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 complexity of financial calculations, no annotations, no output schema, and moderate schema coverage, the description is incomplete. It lacks crucial context like output format, error handling, and differentiation from similar tools, making it inadequate for reliable agent use without additional inference.

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 67% (2 out of 3 parameters have descriptions in the schema). The description adds no parameter information beyond what's in the schema. Since schema coverage is moderate, the baseline is 3—the description doesn't compensate for the partial coverage but doesn't make it worse either.

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 'Calculate Modified Internal Rate of Return' clearly states the verb ('Calculate') and the specific financial metric ('Modified Internal Rate of Return'), which is more specific than just 'MIRR'. However, it doesn't differentiate from sibling tools like 'calculate_irr' or 'calculate_npv', leaving ambiguity about when to choose this specific IRR variant over others.

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. With siblings like 'calculate_irr' and 'calculate_npv' available, there's no mention of MIRR's specific use cases (e.g., addressing multiple IRR issues, different reinvestment assumptions) or prerequisites. This leaves the agent without context for tool selection.

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