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

Annotations already cover the read-only, idempotent, non-destructive profile. The description adds useful return-shape context (case name, docket, author, disposition, citation status, full text, version history with SHA-256 and retrieval timestamps), which matters since there is no output schema. It does not mention auth or rate limits, so not a full 5.

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-loads the core action and identifiers, then lists returned fields compactly. The final sentence on older citations is useful but slightly tangential; overall tight with minimal waste.

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 no output schema, the description does the work of enumerating returned fields and version-history detail. It covers source, coverage range, and fallback, leaving only auth/limits undisclosed, which is minor for a 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?

Schema description coverage is 100%, so the schema already documents all four parameters (item_id, version, citation, max_chars) including the version cross-reference to versions[]. The description's citation examples add little beyond what the schema/examples block provides, so baseline 3 is appropriate.

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 (Read) and resource (Arkansas Supreme Court or Court of Appeals opinion), plus the exact identifiers accepted (neutral citation or archive item id). Clearly distinguishes itself from siblings like ark_recent_opinions and ark_search_opinions, which are named as sources for item_id.

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?

Explains when to use it (retrieve a single opinion by citation or id) and notes the coverage boundary (decisions from 2026-01-01 on). It routes older citations to an external 'court-listener lookup_citation' tool, which is an explicit alternative though not a listed sibling.

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