Get Ticket Link

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

The description adds valuable behavioral context beyond annotations: 'On mobile with SBB app installed, opens directly in the app with Halbtax/GA applied automatically.' This discloses platform-specific behavior and default discounts. It aligns with annotations (readOnlyHint=true, no destruction). No 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 concise with three sentences, each serving a clear purpose: first states the core function, second provides usage guideline, third adds mobile behavior. No unnecessary 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?

Given the tool has 9 parameters and no output schema, the description is fairly complete. It explains the output (a direct purchase link) and special mobile behavior. However, it lacks information about error handling, or what the link looks like, which could be useful. Still, it covers the essential aspects.

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%, so the baseline is 3. The description does not add significant meaning beyond the schema; it mentions the link is for a specific ticket but does not explain how parameters like reduction_card affect the generated link. The description is adequate but not enriching.

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 clearly states the tool's purpose: 'Get a direct purchase link to buy a train ticket on SBB.ch.' It specifies the verb 'Get' and resource 'direct purchase link', and distinguishes from siblings by stating 'Only call this when the user wants to buy a specific ticket.'

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 says 'Only call this when the user wants to buy a specific ticket.' This provides clear context for when to use the tool. However, it does not explicitly mention alternatives or when not to use it, though the sibling tool names (e.g., get_prices, get_trip_details) imply such distinctions.

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