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

With no annotations, the description carries the full burden. It usefully discloses data provenance ('each entry includes a source') and a timeliness caveat (official announcements prevail), which is real behavioral context, but it omits scope, freshness window, result count, and return-shape details for what is clearly a read-only listing.

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 dense sentence that front-loads the resource, then supplies examples and the official-announcement caveat. No filler, though the chained parenthetical and clause stacking make it slightly run-on.

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 no-annotation, no-output-schema listing tool with one optional parameter, the description covers what the data is and where it comes from, which is the essential minimum. It still leaves the agent guessing about how many entries return, ordering, and pagination behavior that an apparently simple list tool may exhibit.

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% for the single optional 'chain' filter, so the baseline is 3. The description's list of channel names (寶雅, 康是美, 屈臣氏, 全聯, 家樂福, Costco) loosely hints at valid filter values, but it is framed as examples ending in '等' rather than an authoritative set, adding only marginal value over the schema.

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 (currently public promotional offers from major Taiwanese chain stores) and enumerates representative retailers, so an agent can distinguish it from price-oriented siblings like get_product_price and list_lowest_prices. The verb is only implied by the tool name rather than stated, and no sibling is named, so it stops short of a 5.

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 explicit when-to-use or when-not-to-use guidance, and no alternative such as compare_chain_prices or search_products is mentioned. The only directional clause, '以官方公告為準' (subject to official announcements), is a data-reliability caveat rather than usage instructions.

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