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

readOnlyHint=true already tells the agent this is a safe, non-mutating computation. The description adds useful context beyond the annotation — that pricing comes from live dealer prices and is the 'today's lowest' snapshot, implying results are time-sensitive. It says nothing about cost, latency, rate limits, or whether the calculation performs network fan-out.

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?

A single front-loaded sentence with no wasted clauses, stating the calculation and its inputs and objective up front. It is slightly padded by branding ('OunceScout Smart Budget Stack Calculator'), but that does not impede comprehension.

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 should convey what comes back; it names the objective (optimal physical stack at lowest live dealer prices) but not the shape of the result — line items, quantities, per-item premiums, or totals. For a simple two-parameter read-only calculator this is adequate, though an agent cannot predict the response structure.

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%, with the strategy enum and budgetUsd both documented, so the schema carries the parameter burden and 3 is the baseline. The description adds only that budget is expressed in USD against live prices; it does not explain allocation behavior such as whether 'balanced' is fixed-ratio or optimized by premium.

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?

A specific verb + resource: it runs a budget stack calculator that returns an optimal bullion allocation for a USD budget using live dealer prices. That clearly separates it from siblings like get_live_spot_prices (prices only) and compare_product_dealers (price comparison), though the siblings are never named.

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?

Usage is implied by the phrase 'for a target USD budget', so an agent can infer this is the planning/allocation tool rather than a lookup tool. There is no explicit when-to-use, when-not-to-use, or named alternative, so the agent must infer the boundary from the description alone.

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