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

Annotations already establish readOnly, idempotent, and non-destructive behavior. The description adds valuable behavioral context beyond those annotations: it explains the traversal direction, that results are returned newest first, and that large result sets are possible for leading cases. No contradiction with annotations exists.

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?

The description is compact, front-loaded with the core mechanism, and every sentence adds value: direction, citation meaning, ordering, use-case guidance, and a volume warning. There is no redundant filler.

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?

For a read-only citation-listing tool, the description covers direction, ordering, use case, and scale. Annotations handle safety, and an output schema exists, so return-value details are not required here. Minor gaps such as explicit pagination advice or explicit sibling differentiation keep it from a perfect score.

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 only 25%, and the tool description does not compensate. It adds no meaning for limit, offset, or response_format beyond their schema titles and defaults, and it only indirectly refers to case_id as 'THIS judgment.' The low coverage means the description should have explained parameter behavior more explicitly.

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 precise verb and resource: 'Walk the citation graph BACKWARD: list later cases that cite THIS judgment.' It also clarifies the semantic content of the citations (followed, distinguished, relied upon), which clearly distinguishes this tool from sibling tools like caselaw_get_citations or caselaw_get_case.

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?

The description gives clear context for when this tool is most useful: 'Most useful on OLDER or landmark judgments' and warns that 'A leading case can have hundreds of citing cases.' It does not explicitly name alternative tools or state when not to use it, but the backward-citation direction and use-case guidance make the intended usage clear.

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