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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds value beyond them: "Keyless" (no auth/credential setup), the fixed size of the result set (37 titles), and the edition/year scope (2026), which tells the agent the data is static and cheap to call.

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?

Two sentences plus a one-word "Keyless." flag, all front-loaded: what it returns, an example, then the routing instruction. Nothing is redundant with the schema or annotations.

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 zero-parameter, read-only catalog tool the description covers return contents (official names, section counts), scope (37 titles, 2026 edition), and its place in the workflow before vi_search. No output schema is needed since the shape of the result is described inline.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The description correctly implies no filtering input is needed.

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?

Starts with a specific verb+resource ("List all 37 titles of the Virgin Islands Code") and disambiguates from siblings by naming vi_search and vi_statute's domain. Concrete examples (Title 14 = Crimes, Title 11A = UCC) make the returned granularity unambiguous.

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?

"Use it to route a subject to a title before vi_search" gives an explicit usage rule and names the downstream alternative, so an agent knows the ordering. It stops short of stating when not to call it (e.g. when a title is already known), so it is clear context rather than full when/when-not coverage.

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