stl_gtfs_files

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

Annotations already declare read-only, idempotent, and non-destructive behavior, and the description is consistent with these. It adds no additional behavioral context such as potential performance implications, data size limits, or side effects, but since annotations are present and adequate, the bar is lower. The description does not contradict annotations.

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?

The description is a single, compact sentence that conveys all core functionality without redundancy or extraneous details. It is well-structured and front-loads the primary purpose, making it easy to parse.

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?

While the description explains what the tool does, it lacks critical context about the 'snapshot' parameter and does not clarify how this tool relates to similar ones (e.g., stl_gtfs_schema or stl_gtfs_stats). The presence of an output schema mitigates the need to describe return values, but the missing parameter explanation leaves an important gap for correct invocation.

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 input schema includes a 'snapshot' parameter with no description, and the tool description does not mention it at all. Since schema coverage is 0% (below 50%), the description was expected to explain what 'snapshot' refers to (e.g., a GTFS snapshot identifier), but it fails to do so, leaving the agent without guidance on how to populate the parameter.

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 states the tool's function: it inventories files in a GTFS zip, including row counts and columns, and lists missing optional files with reasons. This is a specific and distinct resource compared to sibling tools like stl_gtfs_schema or stl_gtfs_stats, making its purpose 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 description implies usage when a high-level file inventory of a GTFS snapshot is needed, but it does not explicitly state when to prefer this over other tools (e.g., stl_gtfs_schema for schema details or stl_gtfs_stats for statistics). No direct comparison or conditions are provided, so guidance is only implicit.

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