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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered structurally. The description adds domain semantics (DPI is realized, RVPI unrealized) but nothing about the result shape, the extra called-percentage output from commitment_usd, or unit conventions. With annotations doing the heavy lifting, this is adequate rather than rich.

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?

Two tight sentences: the first defines the outputs, the second routes to alternatives, and a reference link trails at the end. Zero filler and the core purpose is front-loaded.

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 usefully tells the agent that TVPI, DPI and RVPI are the returns, which is enough to interpret results. The one omission is that commitment_usd also produces a called percentage, so an agent cannot anticipate that secondary output without reading the schema.

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 100%, with every property documented (including the exclusiveMinimum on paid_in_usd and commitment_usd's 'used only for the called percentage'). The description adds no parameter-level detail beyond the metric definitions, so baseline 3 applies.

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 a specific resource (fund performance multiples for an LP or fund) and enumerates the exact metrics computed — TVPI, DPI, RVPI — with parenthetical expansions. It also explicitly separates itself from moic (single deal) and xirr (time-weighted returns), so an agent can choose it without opening a schema.

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?

Names two concrete alternatives with the condition that selects each: moic for a single deal, xirr for time-weighted returns. It does not say when TVPI/DPI is the wrong choice versus irr or cash_on_cash, but the routing guidance it does give is explicit and actionable.

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