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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety and open-world profile is covered. The description adds the licensing/source-attribution angle, which is useful context, but it doesn't describe output shape or any other behavioral traits beyond what annotations provide. With annotations doing most of the work, a 3 is appropriate.

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?

Two tight sentences: the first defines the behavior, the second gives the usage trigger. No filler, front-loaded with the core action.

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?

The tool is simple (one required param, output schema present), and the description covers what the tool does and when to call it. Since an output schema exists, it need not explain return values. Minor gap: no explicit mention of the discover_search sibling relationship.

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 description coverage is 100%, so the single parameter ('type', described as 'which catalogue') is already documented in the schema. The description mentions 'a data type' which loosely maps to the parameter but adds no syntax, format, or enumeration detail. Baseline 3 when the schema carries the load.

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 action: it reveals which public sources underlie a Discover answer and under what licence. That is a clear verb+resource. It doesn't explicitly differentiate itself from the closest sibling, discover_search, but the focus on sourcing/licensing is distinct enough.

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?

It gives clear usage context: 'Use when the user asks how we know something, or whether the information can be trusted.' That is a solid when-to-use condition, though it does not state when-not-to-use or name discover_search as the alternative.

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