Evaluate lawful light displays

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

Annotations already mark the tool read-only and idempotent; the description goes much further by explaining how multiple lawful displays are represented, that all options are equally correct, that 'shall' and 'may' lights are not merged, and that results are verbatim from a pre-release data package. No annotation contradiction.

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 the tool is complex and nearly every sentence carries a distinct caveat or output detail. It is front-loaded with the purpose and returns, though the density of the prose makes it harder to scan than a bulleted structure would be.

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?

Given there is no output schema, the description thoroughly explains return fields, relation semantics, option numbering, optional additions, citations, coverage limits, and data stability. It lacks a concrete call example and does not discuss invalid/empty fact inputs, but is otherwise complete for typical use.

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 0% schema description coverage, the description compensates by naming the core fact fields (propulsion, activity, position, length), referencing the facts data package, and adding the crucial semantic that the input describes a situation, not a fitted vessel, so equipment choices are not settled. Per-field value details are left to the input schema, which provides them.

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 description explicitly states the tool evaluates every complete lawful set of navigation lights from a fact record under COLREGS, and enumerates the returned data (applied entries, exemptions, lawful_displays). This makes the tool's purpose unambiguous and distinguishes it from a generic rule-text or single-light tool.

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 clear when-to-use context (COLREGS Part C lights at night, from a fact record) and explicit exclusions (no day shapes, sound signals, or Part B rules). It does not name sibling tools or explicitly route to alternatives, which prevents a 5.

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