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

Annotations already declare readOnlyHint=true, idempotentHint=true and non-destructive, so safety burden is low. The description adds the meaningful behavioral detail that annualization only occurs when a holding period is supplied, which is context beyond the annotations. It doesn't mention edge cases like a zero/negative return, so not a 5.

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 definition and formula are front-loaded in one dense sentence, with usage routing second. The trailing promo URL is wasted tokens for an agent but doesn't obscure the core content.

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?

With no output schema, the description still tells the agent what comes back: an MOIC multiple and, when years is given, an implied annualized return. For a simple 3-parameter read-only calculator this is close to sufficient; only edge-case behavior is left implicit.

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 coverage is 100%, so the baseline is 3; the description earns above that by explaining that 'years' drives the implied annualized return and defining value_returned as distributions plus current holdings value in the context of the MOIC formula. It adds interpretive meaning rather than repeating 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?

States the exact metric and its formula ('total value returned (distributions plus current value) divided by the amount invested'), a specific computation an agent can match to a user request. It also explicitly distinguishes itself from the sibling tvpi_dpi by scoping that one to fund-level LP multiples.

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?

'Use tvpi_dpi for fund-level LP multiples' routes the agent to the correct alternative, and the mention of 'implied annualized return when a holding period is given' signals the deal-level use case. It lacks an explicit when-not statement (e.g., use irr/xirr for cash-flow-timed returns), so it falls short of 5.

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