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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower. The description still adds real behavioral context beyond them: it declares the tool is arithmetic-only, will not fetch or store anything, does not verify balances, and returns withheld-cash reasons — exactly the information an agent needs to avoid treating the output as authoritative settlement state.

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 dense sentences with no filler; the input enumeration is front-loaded and the scope disclaimer closes it. The telegraphic style is efficient, though a few fragments ('aware ISO clocks') cost parseability for little gain.

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 17-parameter, 16-required tool with no output schema, no parameter descriptions and no worked output shape, the definition is thinner than ideal. It signals withheld-cash reasons exist but never explains what a 'gate' outcome is or how cleared/access_restricted/pledged interact with cutoff and validity windows, leaving the agent to guess at the core logic.

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% with 17 parameters, so the description must compensate. It does add genuine semantics — fineness bounded to (0,1], FX expressed per USD with USD=1, bid in USD per troy ounce, clocks as timezone-aware ISO — but leaves fx_fee_bps, quote_currency, max_quote_age_seconds and the three gating booleans (cleared, access_restricted, pledged) unexplained despite 'gates' being the tool's central concept.

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 and computation: gold sale cash gates computed from decimal kg, fineness, USD/oz bid, fees and FX. The 'gates' framing plus the closing 'Arithmetic and withheld-cash reasons only' makes the tool's nature (pure calculation, not a data source) unambiguous, and the gold domain clearly separates it from the crypto/venue siblings.

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 rather than stated: an agent infers it should call this when it needs gold sale proceeds or cash-gating outcomes from supplied inputs. The negative scoping ('no fetch, storage, execution or verified balance') is helpful, but no sibling alternative is named and no precondition or when-not condition is given.

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