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

Annotations already cover the safety profile (readOnly, idempotent, closed-world), so the description earns credit for adding behavior annotations do not carry: the hard cap of 10 results ranked by popularity, and the AND semantics of filter combination. It stops short of explaining how to reach results beyond the top 10.

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 with zero padding; scope, filter behavior, and result limits are each stated once and front-loaded in the order an agent needs them.

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 no output schema, the description does its job by disclosing the result shape (10 most popular matches) and how to widen the result set. The absence of any pagination or offset parameter, and the lack of guidance on retrieving beyond the top 10 other than loosening filters, is the main remaining gap.

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 each of the six parameters is already documented with defaults and accepted values. The description's only added semantic is that filters combine with AND, which is a genuine but small increment over 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?

States a specific verb and resource ('Find board games in the Kallax.io catalogue'), which is concrete and immediately actionable. It does not, however, differentiate itself from the sibling search_collection, which an agent could reasonably confuse with catalogue search.

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?

Explains that all filters are optional and AND-combined, and tells the agent what to do when the result set is too small ('narrow the filters to see others'). It gives clear operating context but names no alternative tool or when-not-to-use condition.

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