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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the safety profile is covered. The description adds a real behavioral fact the schema cannot convey: omitting the code returns an index rather than erroring or defaulting to a single state. It does not describe response shape or whether results are cached/static, but for a read-only lookup the mode disclosure is the material item.

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 short, front-loaded sentences with no filler; the content list comes first and the mode instruction second. Nothing is wasted, though the sentence is a fragment and could have used a verb to make the action unambiguous.

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 one-parameter, annotation-covered, read-only lookup with no output schema, the description covers what is returned topically and how the absent-parameter case behaves. An agent has enough to call it correctly; only the exact return structure is unstated, which is a minor gap given the listed content categories.

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 100% and the single parameter ('code') is already documented with an example ('NH'). The description's 'omit code for the index' adds meaning about the optional case that the schema does not state, but it gives no format guidance or error behavior for invalid codes, so it sits at the baseline-plus level.

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 names the resource (US state boating rules) and enumerates the specific content covered: registration, titling, boater education, BUI, PFD notes, agency links. That is enough to distinguish it from siblings like get_safety_checklists or get_waterway. It lacks an explicit verb ('retrieve'/'look up'), which keeps it just short of a 5.

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 only usage instruction is 'Omit code for the index', which usefully explains the no-parameter mode. There is no statement of when to prefer this over the other lookups (get_waterway, get_safety_checklists) or any prerequisite context; the sibling separation is implied by the topic list rather than stated.

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