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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful behavioral context: the values are EUR collector valuations rather than retailer prices or predictions, which prevents misreading output. It does not describe freshness, coverage or how valuations are computed, so beyond the currency/nature caveat it is moderate.

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?

Three short sentences, front-loaded with the gating condition and the routing instruction, with zero filler. The one inefficiency is that the opening is a usage restriction rather than a statement of what the tool returns, so the reader learns what it is for before learning what it does.

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 structure need not be described, and the sibling routing is fully handled. What is missing is only the semantic gap around range/price_basis and a direct statement of what 'collector valuation' output represents over the selected range; for a read-only open-world lookup this is close to complete.

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 coverage is 40%, so the description must compensate. It partially does: stating all values are EUR clarifies that the market enum (DE/AT/CH/GB/US/...) does not change currency, which is a real ambiguity the schema leaves open. However, range, price_basis and the relationship between market and collector valuation are not explained anywhere, leaving half the parameters underspecified.

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 frames the tool around 'explicit collector, resale or sealed-set market-valuation requests' and later clarifies 'Values are EUR collector valuations, not retailer prices or predictions,' which pins down the resource. But it never states the verb/return shape directly (a history series? a single valuation?) and its reference to 'price history' as belonging to another tool actively works against the name get_price_history, leaving the actual output somewhat vague.

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?

Explicit routing: use only for explicit collector/resale/sealed-set valuation requests; for price history, price development, Preisentwicklung or past shop prices call get_retail_price_history first; and 'Never use this tool as a fallback for partial or unavailable retailer history.' Both the when and the when-not are stated with the named alternative.

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