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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds real context beyond that: prices are indicative 'from' prices, quoted in rand, split into once-off and monthly, and free-with-package add-ons are counted as zero. It does not say what happens with unknown or unavailable item ids.

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 tight sentences with the core operation front-loaded and the pricing caveat immediately after. No redundant restatement of the title and nothing that could be cut without losing meaning.

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 single-parameter, read-only calculation with no output schema, the description covers inputs, currency, price basis and the free-add-on rule. The main remaining gap is the shape of the result (whether it returns separate once-off and monthly totals), which is only hinted at.

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?

There is one parameter with 0% schema description coverage, so the description must carry the load. It explains that item_ids is a list of item ids to be totaled and that free add-ons contribute zero, but it does not clarify id format, where ids come from (e.g. search_catalog results), or behavior when the list mixes package and standalone items.

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 verb ('Totals') and resource ('from' prices for a list of item ids) plus the currency and the two price components. It is clear what the tool does and is distinguishable from get_item or search_catalog, though it does not explicitly name a sibling it is not.

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: call this when you have a set of item ids and want a bundled price rather than individual lookups. There is no explicit when-not guidance, no mention of alternatives such as get_item for single-item pricing, and no prerequisites stated.

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