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

Annotations already cover read-only, idempotent, and closed-world, so the description doesn't need to repeat safety traits. Instead it adds genuinely useful conditional behavior: opinion text appears only when the extract has a body, and author appears only when that index is loaded. The clarification that 'author' means the slip byline rather than the trial judge or holding is exactly the kind of non-obvious detail annotations cannot convey.

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 short sentences, front-loaded with what the tool returns, followed by the two conditional caveats. Dense but efficient; the phrasing ('Includes author when that index is loaded') is slightly elliptical but never wasteful.

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?

An output schema exists, so return shape need not be explained, and the description fills its remaining obligations: identifying the key type and disclosing the two conditions under which fields are present. Only the source of a valid cluster id and the failure behavior for an unknown id are left unstated.

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 0% and the single parameter has no title beyond 'Cluster Id', so the description must compensate. It does partially by qualifying the value as a CourtListener cluster id (not a state or citation identifier), but it gives no format, example, or note on where to obtain one.

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: retrieve one Indiana opinion cluster keyed by CourtListener cluster id. This clearly distinguishes it from the search/list siblings such as case_search and the citation-graph tools, though it never names them explicitly.

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?

Usage is only implied: 'by CourtListener cluster id' suggests this is a lookup-by-id tool, and the contrast with case_search is inferable from the name. There is no explicit when-to-use/when-not or statement of what to do if you only have a citation (ic_resolve_citation) or need related cases.

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