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

Annotations already establish readOnly/idempotent/non-destructive, but the description adds far more than they do: results are never clearances, negative history is unverified with known false positives, quote matches use a nearest-neighbour join with attribution_distance, protected-info hits are not rulings, and the document is not stored or logged. It also discloses hard bounds (200 citations, 25 detailed flags, flagged_without_detail, citations_truncated) and the 2026-09-30 collection cutoff, which prevents misreading an empty result as 'no such case'.

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 purpose is front-loaded and the body is organized by labeled blocks (reported_negative_history, quotes[], protected_info, Bounds), so an agent can scan to the section it needs. It is dense and clause-heavy and could be tightened, but with no output schema much of the detail is load-bearing rather than filler.

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 must carry the full return-value contract, and it does: per-citation statuses, quote statuses and their caveats, protected-info fields, truncation limits, and the guaranteed headline/note/coverage_note envelope. Nothing an agent needs to interpret a response correctly appears to be 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?

Only one parameter exists and schema coverage is 100%, with the schema already documenting the 380,000-character cap and the refuse-rather-than-truncate behavior. The description adds nothing about the 'text' parameter specifically, so the baseline of 3 applies; the richer semantics it does provide are about outputs, not inputs.

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 first sentence names a specific verb and resource ('checks the case citations in a document the user supplies') plus the concrete input artifact (draft filing, brief or motion) and the decision it supports (which cases to read before filing). That is clearly distinguishable from siblings like citation, citations and treatment, which operate on individual citations rather than a whole document.

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?

It gives a clear usage context (pre-filing review of a user-supplied draft) and rules out expectations by listing what is not checked (short forms, statutes, rules, secondary sources, block quotations). It also points to adjacent tools ('Negative-history limits are those of the treatment tool' and 'The sources tool returns this tool's full coverage statement') but never states an explicit 'use X instead when Y' routing rule.

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