Koleo MCP Server

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

With no annotations provided, the description carries the full burden and discloses the sorting behavior ('sorted by time') and dual-direction scope. However, it omits other behavioral details like pagination, date null-handling, or whether data is real-time versus scheduled.

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?

Single sentence of 12 words with zero waste. Every clause earns its place: operation ('Get all trains'), sibling differentiation ('both departures and arrivals'), parameter context ('at a station'), and behavior ('sorted by time').

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 only two parameters and an output schema exists (relieving the description from explaining return values), the description is minimally adequate. However, with 0% schema coverage, it should have explained the date parameter semantics to be complete.

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 0%, requiring the description to compensate. While 'at a station' implies the station parameter, the description completely omits explanation of the 'date' parameter, its format, or the significance of the default null value.

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 specific verb 'Get' and resource 'trains', and explicitly distinguishes from siblings tool_get_arrivals and tool_get_departures by stating it returns 'both departures and arrivals', making the scope 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 parenthetical '(both departures and arrivals)' provides clear implicit guidance on when to use this versus the specific arrival/departure sibling tools, though it lacks explicit 'when to use' phrasing or prerequisites.

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