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

Goes well past the annotations (which already cover read-only, idempotent, non-destructive). It discloses that products may be empty because only partner shops permitting redistribution are included, that siteSearchUrl carries live prices for all shops, that links must be passed on unchanged, and that language falls back to English when the site does not support the requested language. These are exactly the behavioral qualifiers annotations cannot express.

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?

Purpose, trigger, return fields and usage rules are front-loaded in the right order, but the entire German block is then repeated in English, so roughly half the text restates the same information without adding anything for an agent. That redundancy is the only real structural weakness.

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 an output schema present and annotations covering safety, the description focuses on the right things and explains the shape and limits of what comes back, so an agent can call it confidently. The remaining gap is routing: it does not say how it relates to lookup_product or find_pages, which matters for a search tool with siblings.

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 100%, so the baseline is 3; the description adds value on the language parameter, advising it be set to the user's language and noting that the result's languages field lists supported options, which goes beyond the schema's iso-code and fallback rule. Other parameters (brand, price bounds, limit, query) are left entirely to 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?

Names a concrete verb and resource: price comparison on wovitamine.de with daily best prices from many shops, and it enumerates the three return fields (siteSearchUrl, browse, products). It is unambiguous on its own, but it never distinguishes itself from the sibling tools find_pages and lookup_product, so it falls 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?

Gives concrete trigger conditions: use it when a user asks about price, Angebot, 'guenstig', 'wo kaufen' or a specific vitamin product. That is clear positive guidance, but it names no exclusions or alternatives, even though lookup_product and find_pages look like competing choices for related intents.

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