calculate_fund_returns

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

With no annotations, the description carries the full burden of behavioral disclosure and does well by explaining the computation logic (NAV on/before investment date, units valued at latest NAV). It also discloses the risk of wrong results from incorrect scheme codes. It doesn't cover error handling or data availability, but provides solid 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 two sentences, front-loaded with the core function, and adds a critical usage caveat. No filler words or redundant details; every sentence earns its place.

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?

For a simple 3-parameter tool with no output schema, the description is largely complete: it explains inputs, computation, and outputs. It could mention edge cases like missing NAV or holiday handling, but it's sufficient for an agent to select and invoke the tool correctly.

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 already describes all three parameters with high coverage, so the baseline is 3. The description adds critical semantic context that schemeCode must originate from search_mutual_funds and never be guessed, and explains the 'on/before' logic for the investment date. This enriches the parameter meaning beyond the schema.

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 it computes real returns for lump-sum mutual fund investments using live NAV history, and specifies the outputs (absolute return, CAGR, XIRR). This distinguishes it from siblings like get_fund_nav which only provide NAV, making the purpose unmistakable.

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 gives explicit instructions that schemeCode must come from search_mutual_funds and warns against guessing, which is a strong usage guideline. It also scopes the tool to lump-sum investments, implying it is not for SIPs. However, it does not explicitly name alternative tools for different calculation scenarios, so it falls short of a 5.

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