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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the ingestion cadence (3 times a day) and the freshness indicator (latest price day per source), which tells an agent whether the underlying data may be stale. It does not describe return format, but that gap is minor relative to what it does add.

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 efficient sentence with no filler, and the key content (which sites are read, at what cadence, and the freshness marker) is front-loaded. It is a fragment rather than a full sentence, but nothing in it is wasted.

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 parameters, no output schema and a simple read-only metadata payload, the description covers the essentials: the sources, the cadence, and the fields per source. Only minor detail is missing (how many sources, exact return shape), which is acceptable given the tool's simplicity.

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?

The tool takes zero parameters, so the baseline is 4 and there is no parameter semantics to compensate for. The description correctly spends its words on the return content instead.

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 the specific resource — the Indonesian dealer websites whose prices FiLot ingests, plus the products and latest price day — so an agent knows exactly what metadata this returns. It doesn't explicitly differentiate itself from siblings like gold_buyback_prices or indonesian_gold_tax, but the subject matter is distinct enough to be identified without opening another 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?

There is no when-to-use guidance and no alternatives are named. The intended use (checking data provenance or whether a price source has gone stale) must be inferred from the phrase 'the latest price day of each', with no explicit framing of when an agent should call this instead of the price siblings.

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