calculate_irr

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. It only states what the tool calculates without mentioning how it behaves—no information on return format, error handling (e.g., for non-converging cash flows), computational limits, or assumptions (e.g., reinvestment rate). This leaves the agent with insufficient operational context.

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 sentence with zero wasted words. It's front-loaded with the core action and resource, making it immediately understandable. This brevity is effective for a straightforward tool, though it may trade off completeness for conciseness.

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's complexity (financial calculation with potential for nuanced behavior) and lack of annotations or output schema, the description is incomplete. It doesn't explain what IRR is, how results are returned, or edge cases, leaving the agent under-informed. While the schema covers parameters, overall context is inadequate for reliable 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 input schema has 100% description coverage, with the 'cashFlows' parameter documented as 'Cash flows including initial investment'. The description adds no additional parameter semantics beyond this, such as examples or constraints (e.g., negative initial investment). Given the high schema coverage, the baseline score of 3 is appropriate, as the schema handles the heavy lifting.

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 Internal Rate of Return' clearly states the verb (calculate) and resource (IRR), providing a basic understanding of the tool's function. However, it doesn't differentiate this tool from its sibling 'calculate_mirr' (Modified IRR) or other financial calculation tools like 'calculate_npv', leaving the purpose somewhat vague in context.

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. It doesn't mention scenarios where IRR is appropriate (e.g., investment analysis), contrast it with MIRR or NPV, or specify prerequisites like cash flow ordering. This absence of usage context is a significant gap.

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