list_linesRetrieve every recorded London rail line (Tube, Elizabeth line, Overground, DLR) with IDs, names, modes, and shared-track details; use IDs to query status, disruptions, and period stats.
Every line Tifa records, with its id, name and mode (tube, elizabeth-line, overground or dlr) and the lines it shares track with. The ids are what line_status, disruptions and period_stats take.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare read-only, idempotent, closed-world, non-destructive, so the safety profile is fully covered. The description adds the useful detail that results are exhaustive ('every line') and what fields come back, but says nothing about ordering, pagination, or freshness. Useful context beyond annotations, but thin.
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?
Two sentences, zero waste: the first enumerates the payload, the second explains the downstream use of the ids. Front-loaded with the core identification.
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?
There is no output schema, so the description must carry the return-value burden — and it does, naming the exact fields and the mode values. For a zero-parameter, annotation-covered read tool, nothing an agent needs is missing.
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?
Zero parameters, so the baseline of 4 applies; there is nothing the description could add on this dimension. The description correctly doesn't waste words on inputs.
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?
States a specific verb (list) and resource (every line Tifa records) and enumerates the returned fields: id, name, mode, and shared-track lines. The mode enumeration (tube, elizabeth-line, overground, dlr) makes it distinguishable from the status-oriented siblings at a glance.
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?
Explicitly says the ids returned are what line_status, disruptions and period_stats take, which strongly implies this tool is the discovery/prerequisite step before those. It stops short of an explicit 'call this first / use when you need line ids' directive, so it lands at 4 rather than 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.