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

Annotations already establish read-only, idempotent, non-destructive behavior, and the description adds substantial extra context: resolution through the reporter index, the name_mismatch problem when expected_case_name disagrees, the up-to-5 candidate limit, and the decisiveness heuristic. This is behavioral disclosure 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?

Front-loaded with the core purpose and the alternative tool, then the resolution rules. It is long and packs many clauses, but nearly every sentence encodes an invariant an agent must know; only the parenthetical example list is slightly heavy.

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?

No output schema exists, so the description enumerates the answer fields (case with bluebook/url/link_md/treatment_flag, kind, decisive, candidates, note). Combined with the decisiveness rules, an agent has everything needed to call and interpret this 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?

Schema coverage is 100%, so the baseline is 3, but the description goes further by explaining how citation strings resolve and what expected_case_name actually triggers (non-decisive answer with name_mismatch). Court and state precedence are already covered in the schema text.

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 (find/lookup) and resource (one case) with the scope 'by citation or caption', and explicitly contrasts itself with search_cases. The single-case resolution goal is unmistakable to an agent scanning siblings.

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?

Explicitly says to use search_cases for topics and words instead, and lays out the conditions under which a caption lookup is decisive (top match at least twice as strong as runner-up) versus not (common captions by design). This is genuine when-to-use/when-not guidance.

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