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

Annotations already declare this a read-only, idempotent, non-destructive operation, so the safety profile is covered. The description adds genuine behavioral context beyond them: the output is shaped as one row per published figure, and a robot that does not publish a figure is rendered null rather than omitted.

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 short sentences, zero filler, and the structural behavior of the result is front-loaded. Nothing is repeated or padded.

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?

There is no output schema, but the description covers the essentials an agent needs: the comparison layout and the null semantics for missing figures. It does not describe ordering of figures or error behavior for invalid robot identifiers, which is a minor remaining gap for a simple read tool.

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?

The schema already documents the 'maker/model' string format and enforces minItems 2 / maxItems 4, and the description's 'two to four' merely restates that constraint without adding syntax or format guidance. With one parameter it does no harm, but it contributes little meaning 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?

States the resource (robots) and the comparison semantics ('side by side, one row per figure'), which is enough to distinguish it from single-robot siblings like get_robot. The verb is implied by the name rather than stated, and no sibling is named explicitly, so it stops short of a 5.

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?

'Two to four robots' implies the multi-robot comparison case, but there is no explicit when-to-use guidance and no routing to alternatives such as get_robot for a single robot or find_robots for discovery. Usage is inferable but not stated.

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