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

With readOnlyHint and destructiveHint=false already covering safety, the description adds meaningful context: it lists returned fields (product keys, pack sizes, cheapest price, shop count), mentions per-result disclosures (affiliate links, price source) and compliance_notice for medicines, and reinforces the 'prices only, no medical advice' scope. It stops short of noting rate limits or error behavior, but for a read-only search this is solid.

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?

The description is front-loaded with the core action, then layers in return contents, disclosures, and scope boundaries across a few tight sentences. Every sentence carries useful information without repetition or fluff, and the 'no medical advice' caveat is appropriately placed at the end.

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?

There is no output schema, so the description must explain return values—and it does: product keys, pack sizes, cheapest price, shop count, plus disclosure and compliance notices. Combined with safety annotations and a fully documented two-parameter schema, an agent has everything needed to invoke this tool correctly.

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%—both query and limit are fully documented in the schema. The description restates the query formats (name, PZN, EAN) but adds no new parameter-level detail such as syntax examples or limit defaults beyond what the schema already provides.

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 states a specific verb (Search) and resource (health products sold by German online shops and pharmacies) with searchable identifiers (name, PZN, EAN). It clearly distinguishes the product-level scope from the sibling offers tool only implicitly via return fields (cheapest price, shop count), without naming search_product_offers as the alternative.

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 description implies usage (search by name/PZN/EAN) and sets boundaries ('Prices only... no medical advice'), but it never explicitly states when to use this tool versus search_product_offers or outlines prerequisites. The guidance is implied rather than spelled out.

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