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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds substantive non-annotation behavior: no external quote verification and no persistence of inputs, which is exactly what an agent needs to know about a simulation tool.

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, no padding. The primary output statement comes first, followed by the crucial caveat about verification and persistence.

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?

An output schema exists, so return values need no explanation, and statelessness is clearly disclosed. The main residual gap is that with 8 parameters at 0% schema coverage, the description does not define units or semantics for the inputs beyond the string-format convention.

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 0%, so the description must compensate. It flags the crucial convention that inputs are decimal strings, which matters given the string patterns, but says nothing about individual parameters such as day_count (enum 360/365), fineness scale, or unit conventions for fees/days.

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 verb ('Calculate') with concrete outputs (fine gold, simple financing cost, INR per fine gram) and the basis (explicit decimal-string assumptions). Sibling tools are mostly unrelated domains, so no routing conflict, though no explicit differentiation is offered.

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 clause 'All inputs are caller supplied, no quote is verified, and inputs are not persisted' tells the agent this is a self-contained deterministic calculation rather than a data lookup, which implies usage. It does not state when to prefer this over alternatives or any prerequisites (e.g., all amounts must be supplied as strings).

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