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

Annotations already mark the tool as read-only, idempotent, non-destructive, and closed-world, and the description adds meaningful behavioral context: unknown ids land in a 'missing' field with a near-miss suggestion, comparison continues with the remaining objects, and missing attributes are represented as null. This goes well beyond the annotations.

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 sentences deliver output scope, usage context, and edge-case behavior with no filler. The most important information—what the comparison includes and when to use it—is front-loaded, and the unknown-id behavior closes the description efficiently.

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 one required parameter, a rich output schema, and annotations covering safety, the description still adds everything needed for correct invocation: when to use it, how to prepare input ids via other tools, what the output contains, and how failures are reported. Nothing essential is missing.

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 schema already documents the ids parameter, including source, cardinality, and column ordering. The description adds extra parameter behavior by explaining how unknown ids are handled and that the rest are still compared, which enriches the semantics beyond 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?

The description states a specific verb (compare), a specific resource (knowledge objects), and a detailed scope: side-by-side cards, indexed attribute matrix, tags, relations, common neighbours, and claims. It also distinguishes itself from siblings by specifying when 'X vs Y' questions call for this tool rather than search or get_topic.

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 usage conditions are given: use when the question is 'X vs Y', 'is X the same as Y', or 'how does X differ from Y'. It also instructs to call search or get_topic first when only names are known and then pass the resulting ids, clearly routing the agent to the correct workflow.

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