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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description does not need to restate the tool's read-only nature. It adds a small behavioral detail by listing the types of disruptions (delays, weather alerts, strikes), which provides context, but it does not disclose any side effects or limitations beyond what annotations already indicate. The description aligns with the annotations.

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, well-structured sentence that front-loads the primary action ('Find all ferry travel disruptions') and packs the scope ('for a given date and country') efficiently. Every word contributes to conveying the tool's purpose without redundancy or 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?

The tool has a clear purpose, two required parameters with thorough schema descriptions, an output schema (so return format is assumed to be known), and annotations covering the safety profile. The description is sufficient for an agent to understand when to invoke it and what inputs to provide. No critical information about calling the tool is missing, though it does not mention any pagination or filtering nuances.

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%, with both parameters (country and tripDate) having clear descriptions including format examples. The description's phrase 'for a given date and country' simply repeats what the schema already documents. It adds no extra meaning beyond the schema, so a baseline of 3 is appropriate.

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 uses a specific verb 'Find' and names the resource 'ferry travel disruptions' with concrete examples (delays, weather alerts, strikes). The tool name 'get_disruptions' is also specific, and it is clearly distinct from siblings like search_trips or trip_details, which focus on connections and itineraries. The purpose is unambiguous.

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 does not explicitly mention when to use this tool versus alternatives, but the purpose is clear enough that an agent can infer it should be used when disruptions are relevant. It does not provide any 'when not to use' guidance or mention sibling tools, so usage is implied rather than explicit.

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