stl_support_explain_empty

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

The description indicates a read-only diagnostic behavior, consistent with the readOnlyHint, idempotentHint, and destructiveHint annotations. Walking a decision tree and naming a branch is clearly non-mutating.

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 concise and well structured, with the purpose, trigger, and argument notes clearly separated. No redundant or extraneous content is present.

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?

The description is mostly complete for the intended use case: it names the diagnostic branches and links to stl_gtfs_departures. Since an output schema exists, return details are not required, but the omitted snapshot and window_minutes semantics leave minor contextual gaps.

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 Args section explains stop and at with format details, but snapshot and window_minutes are not described. Schema defaults provide some inference for window_minutes, yet snapshot's role in the diagnosis is left unclear.

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's purpose: diagnosing why a stop has no departures. It names the exact decision branches and explicitly connects it to stl_gtfs_departures returning an empty list, distinguishing it from the related departure-query tool.

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?

It gives a direct usage trigger: use whenever stl_gtfs_departures returns an empty list. It does not explicitly say when not to use the tool, but the trigger and 'instead of guessing at the cause' provide enough guidance.

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