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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses the data source freshness (refreshes from published notices), the nature of returned data (active and upcoming notices with dates, authority, navigation-blocking status, links), and implies this is a read-only operation. It doesn't mention error handling or pagination, but the covered traits are meaningful.

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 a single, somewhat dense paragraph, but every sentence contributes: scope, search options, return contents, and data refresh policy. It could be improved with bullet points for scannability, but it remains concise and information-dense without fluff.

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 and no annotations, the description covers the essential context: what data is returned, how to search, and the freshness of the data. It doesn't fully cover edge cases like empty results or maximum radius behavior, but for a straightforward lookup tool, it is largely complete and well contextualized.

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?

While the schema already documents all three parameters (100% coverage), the description adds critical usage semantics by clarifying that place and waterway are mutually exclusive ('Give this or waterway'), explaining the coordinate format ('lat,lon'), and noting the optional radius with a default. This enriches the parameter understanding beyond the schema.

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 returns live closure, stoppage, and restriction notices for British waterways, lists specific authorities to emphasize broad coverage, and contrasts with a common assumption (not just CRT). It also names the search methods and return contents, making its purpose unmistakable and distinct from sibling tools like plan_route or find_place.

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 gives clear search instructions: by place (name or lat,lon) with optional radius, or by waterway name. It also highlights coverage across all navigation authorities, which helps when to prefer this over a more limited tool. However, it doesn't explicitly mention when not to use it or contrast with alternatives, so it falls short of a 5.

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