transit_departures

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

Annotations already declare readOnlyHint=true, destructiveHint=false, etc. The description adds context about real-time delays and data sources but does not disclose additional behaviors like return format, rate limits, or data freshness beyond 'minutenfrisch'.

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, front-loading the key differentiator. It could be more structured but remains efficient.

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's complexity (live transit data) and minimal schema (2 params, no output schema), the description adequately explains the tool's purpose, parameters, and differentiation from siblings. It is complete enough for an agent to use.

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?

With 0% schema description coverage, the description compensates by explaining the slug as a city slug and stop_id as optional, noting that omitting it returns city-level departures.

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 states it provides live departures with real-time delay for a stop, using specific data sources (GTFS-RT/HVV/VGN). It explicitly distinguishes itself from the sibling tool 'transit' which provides static stops.

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 clearly explains when to use this tool over 'transit' (for real-time data) and mentions the optional stop_id parameter. However, it does not explicitly state when not to use this tool or provide exclusions.

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