ns-bridge

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 effectively describes what the tool returns (real-time updates about delays, cancellations, and platform changes) and provides detailed return structure. However, it doesn't mention potential limitations like rate limits, authentication requirements, or error conditions that might be important for an agent.

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 well-structured with clear sections (purpose, usage, args, returns, examples) and every sentence adds value. It's appropriately sized for a tool with 3 parameters and detailed return structure, with no redundant or unnecessary information.

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 (real-time data with multiple parameters) and the presence of an output schema, the description provides complete context. It covers purpose, usage guidelines, parameter semantics, and return structure. The output schema handles the detailed return format, so the description doesn't need to duplicate that information.

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 fully compensates by providing detailed parameter documentation. It explains what each parameter means, provides examples (e.g., 'ut' for Utrecht Centraal), specifies defaults (10 for max_journeys, current time for date_time), and gives constraints (max: 40). This adds significant value beyond the bare 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 clearly states the tool's purpose with specific verb ('Get') and resource ('upcoming train departures for a specific station'). It distinguishes from sibling tools by focusing on departure information rather than station search or trip planning, making it easy for an agent to understand when this tool is appropriate.

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 'Use this to check the departure board at a station' and provides a clear alternative ('Use search_stations to find codes') for one of the parameters. It distinguishes from sibling tools by focusing on real-time departure information rather than station search or trip planning, giving the agent clear guidance on when to use this specific tool.

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