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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and openWorld. The description adds genuinely new behavior: results are limited to items 'currently out of service' rather than a full inventory, plus the answer-only constraint and the unofficial-source disclaimer. It still omits whether outage details include location, cause, or expected restoration, but that may be covered by the output schema.

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 scope statement is front-loaded in the first sentence, with the guardrails and disclaimer separated into a second short block. Both blocks are short and purposeful, though the disclaimer is more policy than tool documentation.

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 an output schema present, return-value shape need not be described, and the tool has a single optional parameter. The description supplies the one behavioral fact that matters (results are outages only) plus usage guardrails, which is sufficient 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?

Schema description coverage is 0%, so the description must carry the param, and it does partially: it says the station filter is optional and limited to one station. It does not clarify whether the value is a station name, code, or free text, nor what happens for an unknown station, so the compensation is only partial.

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 first sentence names the exact resource (elevators and escalators) and the state being reported (currently out of service), which is far more specific than the title alone. It does not explicitly differentiate itself from get_service_alerts or get_station_info, so an agent must infer the boundary, but the resource is 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 only usage signal is 'optionally for one station', which hints at filtering but says nothing about when to choose this over get_service_alerts or get_station_info. There are no exclusions, prerequisites, or named alternatives, leaving the agent to guess which outage-related sibling to call.

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