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

With no annotations, the description carries the burden alone; it does disclose what the call returns (fact ids plus verification states), which is genuinely useful behavioral context. However, it says nothing about scope (all facts vs. a subset), ordering, pagination, or cost, so the disclosure is partial.

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 short sentence, front-loaded with the verb and the returned fields, with no filler. The parenthetical domain tag is slightly cryptic but efficient; the terseness borders on under-specification rather than padding.

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?

With no parameters, no annotations, and no output schema, the description is the sole source of behavioral information, and it covers only the returned fields. It leaves unclear how the id list relates to railcomp_get_fact and railcomp_changes, which an agent needs to chain calls correctly.

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 the baseline is 4 and there is no schema gap for the description to compensate for. The description also correctly implies there is no filtering input, reinforcing the no-argument nature of the call.

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 (fact ids), plus the extra returned field (verification states) and a domain tag (railcomp). It is distinguishable from siblings like railcomp_get_fact and railcomp_changes, though it does not name them explicitly.

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 statement of when to use this versus railcomp_get_fact or railcomp_changes; the agent must infer that listing ids is the discovery step before fetching a single fact. No exclusions, prerequisites, or alternative routing are given.

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