Data sources, coverage and licences

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and openness profile is covered structurally. The description adds scope context (validity dates, licence/attribution metadata) beyond the annotations, but says nothing about response format, freshness of the data, or why open-world behavior matters here. Adequate but not rich.

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 compact sentence with no redundancy, and the most important content (which feeds are loaded) is front-loaded. The telegraphic noun-phrase style is slightly less readable than a full sentence but costs no extra tokens.

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?

For a zero-parameter, read-only metadata tool with no output schema, the description effectively does the work of documenting the return payload by naming the fields the agent will get back. It would be complete if it also signalled that no arguments are accepted, but overall it covers what an agent needs to call it.

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?

The tool takes zero parameters, so there is no parameter semantics to explain, which is the baseline-4 case. Nothing in the description misleads about 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?

The description names a concrete domain and enumerates the exact content returned: loaded carriers/feeds, validity dates, licences, required attribution, and enable-able feeds. It is clearly distinguishable from the journey/departure/stop siblings, though it is written as a noun fragment rather than a verb-led statement of what the tool does.

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?

There is no explicit when-to-use guidance, no prerequisites, and no named alternatives. The phrase 'which feeds can be enabled' hints at a provenance-checking workflow before plan_journey, but the agent must infer that entirely; nothing in the text tells it when this tool is the right choice over the siblings.

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