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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful non-structured context: the v1 index only covers the U.S. Reports reporter, a material scope limitation, plus a summary of what is returned (metadata with CAP ids and citations).

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 tight sentences, front-loaded with purpose and filters, then the follow-up action, then the scope caveat. No filler or redundancy.

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, and the description compensates by stating the return shape (case metadata with CAP ids and citations) and the critical index-coverage limitation. Combined with annotations and a fully documented schema, 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 description coverage is 100%, so all six parameters are documented with examples and bounds in the schema itself. The description names the filter dimensions but adds no syntax, format, or combination rules beyond what the schema already provides, so the baseline of 3 applies.

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 and resource (search US court opinions) and enumerates the filterable dimensions (case name/keyword, court, jurisdiction, date range). It also distinguishes itself from the sibling caselaw_opinion_text, so an agent can route without opening the schema.

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 names the alternative and the condition for using it: 'Use caselaw_opinion_text with a returned id to read the full opinion.' That is clear routing, though there is no explicit when-not-to-use guidance or mention of the other caselaw siblings (case_details, citation_lookup).

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