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

Annotations already declare readOnly, idempotent, non-destructive and closed-world scope, so the safety profile is covered. The description adds real behavioral value by disclosing that results are contextualized against a stored price history, i.e. the output is an evaluation, not just a listing. It does not mention data freshness or what happens when no price history exists for a product.

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 compact sentences, front-loaded with the action and followed by the user-intent framing. Something is trimmed that could help (what the ordering/coverage is), but nothing present 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?

For a single-parameter, read-only lookup with no output schema, the description conveys enough: what is searched, where, and that a price-history verdict comes back. Minor gaps remain around result volume, currency/region confirmation and empty-history behavior, but an agent can invoke it correctly from this.

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% and the single parameter already carries an example including a conditioned query ('oled 55 unter 900'), so the schema does the heavy lifting. The description implies natural-language queries are accepted via 'Wo gibt es X gerade?', but adds no syntax, matching or fallback guidance beyond that.

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?

States a specific verb and resource — searches current tech offers from German shops on VoltDeal — and adds a second distinguishing action: it ranks the price against the recorded price history. This is clearly more than a restatement of the name 'preis_check' and tells an agent exactly what capability it gets.

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?

The second sentence gives concrete trigger questions ('Ist der Preis gut?', 'Wo gibt es X gerade?'), which makes the intended use case explicit. It stops short of stating exclusions or limits (e.g. non-tech products, non-German shops), but with no sibling tools there is no alternative to route to.

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