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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered; the description adds value by enumerating the returned public profile fields and stating the minimum-input constraint. It does not describe pagination semantics beyond the schema or what error surfaces when both filters are omitted, which keeps it short of a 5.

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 purpose, then return shape, then the input constraint. No redundant restatement of the tool name or annotations.

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 five-parameter read-only search with no output schema, the description covers purpose, filters, return fields, and the key input constraint, which is enough to call it correctly. The remaining gap is the relationship to get_shop_details for full profile retrieval.

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, but the description adds real meaning the schema lacks: the schema marks query and country as optional-with-null-default, while the description imposes a cross-parameter requirement that at least one be supplied. It also clarifies that query matches name or website keyword, slightly beyond the schema's phrasing.

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?

"Search retail shops listed on Vaper.club by name/website and/or country" gives a specific verb, a specific resource, and the filter dimensions, which cleanly separates it from search_brands and search_products by resource alone. It also names the returned fields (website, locations, product count, rating), so an agent knows what it gets back without opening the schema.

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 definition states a hard precondition ("At least one of query or country is required"), which is genuine usage guidance an agent could otherwise get wrong. However, it gives no routing guidance versus get_shop_details, which is the obvious next step once a shop is identified, so the when-to-use picture is only implied.

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