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

Beyond the annotations (read-only, idempotent, non-destructive), the description discloses the ranking order, the risk of over-reading early CJEU-heavy results, pagination via offset and pagination.next_offset, the citing_rn semantics, and the coverage limitation where total: 0 can mean 'not indexed' rather than 'no citations'. This is substantial behavioral context.

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?

The description is long, but every paragraph earns its place: core instruction, ranking caveat, result semantics, and coverage warning. It is front-loaded with the essential either/or usage first. A slight trim of the 'Read the ranking honestly' phrasing would make it tighter.

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 tool with no output schema, the description provides the needed return-value hints (total, pagination.next_offset, coverage.complete_for_this_norm, citing_rn) and the coverage limitations that are critical for interpreting results. Nothing an agent needs to call this correctly and interpret its output is missing.

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?

With only 40% schema coverage, the description compensates by clarifying the mutual-exclusivity of law+ref versus case, how offset interacts with pagination.next_offset, and what results represent. It does not add much on the limit parameter, but the schema already supplies default and bounds, and limit is self-explanatory.

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?

The opening phrase 'Incoming citation edges' plus the explicit 'EITHER law + ref OR case' formulation states exactly what the tool lists and what inputs select each mode. It clearly distinguishes the tool from the likely outgoing-citation sibling (listCitedAuthorities) by framing this as the incoming direction.

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?

The description explains when to use law+ref versus case, and gives an explicit fallback to 'search' for Land provisions when coverage is incomplete. It does not explicitly name or exclude sibling tools like listCitedAuthorities, but the directional language and coverage guidance are strong enough for correct routing.

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