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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds only the word 'latest', hinting at freshness but disclosing nothing about caching windows, refresh cadence, or whether the premium is computed from live spot data.

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?

One tight sentence with no redundant or padded content. It front-loads the primary output (the premium multiple) before the derived value.

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 not be explained, and the schema covers the single parameter. What is missing is routing context against sibling tools that also expose premium or price data, which an agent would need to pick this tool correctly.

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%: the single optional 'base' parameter is fully documented in the schema, including its default of USD and a pointer to the currency catalog. The description adds no parameter meaning beyond that, so the 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?

The description names a specific resource and its two outputs: the Goldback premium multiple over gold content and the derived exchange rate. It is a noun phrase rather than a verb+resource, and it does not distinguish itself from the sibling get_observed_premiums, which also concerns premiums, leaving some ambiguity about which premium figure is which.

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?

No when-to-use guidance, no prerequisites, and no mention of alternatives such as get_observed_premiums or get_spot_prices, despite those siblings appearing to overlap conceptually. The agent is left to infer selection criteria entirely.

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