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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds the fact that results are normalized cards with a specific field set and that URL handoff to chrono24_listing is expected. It does not mention pagination semantics beyond the schema's Page/PageSize, nor rate limits, so it stops short of full behavioral disclosure.

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?

Single front-loaded paragraph that leads with the core capability before routing and filter detail. It is dense but almost every clause carries information; the long enumeration of filter names is the only mildly redundant part since the schema lists them too.

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, the description need not explain return values, yet it summarizes card fields anyway. Annotations cover safety. The remaining minor gap is pagination/ordering guidance for Page and PageSize, which is left entirely to the schema.

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 baseline is 3. The description still adds value: it explains the query/brand/model relationship, states relevance is the default sort, and clarifies that the advanced filters map to the chrono24_facets value groups. That extra semantic context lifts it above the schema-only baseline.

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 opens with a precise verb+resource ('Search Chrono24's luxury-watch marketplace') and immediately distinguishes the two modes: free-text keyword vs. brand/model browsing. It also enumerates the normalized result card fields, so an agent knows exactly what it gets back and how it differs from sibling tools like chrono24_listing.

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 rules are given in-line: 'At least one of query or brand is required', 'model (from chrono24_models) narrows within brand', filter values come 'from chrono24_facets', and the listing url is 'to pass to chrono24_listing'. The agent is told both when to use each parameter and which sibling to call next.

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