tfl_line_status

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

With no annotations, the description must disclose behaviors. It reveals the authentication requirement (TFL_APP_ID/TFL_APP_KEY) but fails to mention rate limits, error handling, caching, or what happens when line_ids is null. Significant gaps remain.

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?

A single sentence covering purpose, scope, data source, and auth is efficient. However, it omits parameter details that could be integrated without bloat. Still, it is well front-loaded and earns its 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 presence of an output schema, return value details are covered. However, the description does not explain what 'line status' entails (e.g., types of disruptions) or how to use the optional parameter. Moderate completeness for a simple tool.

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 coverage is 0%, so the description must explain parameters. It does not describe the format of 'line_ids' (e.g., line names, IDs, or separation style) nor the default behavior when null. This leaves the agent guessing.

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 identifies the tool as returning line status for London tube/DLR/tram via TfL API. It distinguishes itself from sibling tools, which cover other UK public data sources, by mentioning the specific API and transport modes.

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 implies usage for checking line status but does not provide explicit guidance on when to use this tool versus alternatives. It mentions the need for API credentials, which is helpful, but no exclusions or when-not-to-use scenarios are given.

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