journey_with_layover

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

With no annotations provided, the description carries the full burden. It discloses the internal behavior: 'Books the first leg ending at the layover, then the next leg starting at layover_minutes after arrival.' This explains the mechanism without requiring inference, though it omits edge cases like connection infeasibility.

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 two short paragraphs: a crisp one-line summary followed by usage examples. Every sentence contributes, and it is front-loaded with the core purpose. No wasted words.

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 4 required params, no annotations, but an output schema does exist, so return values don't need explanation. The description covers purpose, usage, and mechanism. It lacks explicit exclusion of alternatives or edge-case handling, but for a booking tool, the core is complete enough to guide an agent.

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?

Since schema coverage is 100%, the baseline is 3. The description adds value by clarifying layover_minutes as 'after arrival' and explaining how the four parameters interrelate (first leg ends at layover_station, next leg starts after lag). This goes beyond the schema's simple field labels.

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 opens with a specific verb and resource: 'Chain two connections with a deliberate layover at a chosen station.' It clearly distinguishes this from sibling tools like get_connections by focusing on intentional layovers and the chaining of two legs.

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 explicitly states when to use the tool: 'Use this tool when the user wants to break a journey on purpose' with concrete examples (grab food, meet someone, sightsee). It provides clear context but does not name alternative tools or when not to use it, 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.