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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered; the description adds the return shape (answer line, confidence, last_observed, basis) and, importantly, that the dated tail prediction is omitted — a real behavioral difference from the sibling. It stops short of saying how stale data can get or whether the underlying answer can disagree with get_wifi_facts, which would complete the picture.

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?

Front-loaded with the identity of the tool and its alternative, and every sentence carries information. The closing 'Otherwise use get_wifi_facts' mildly restates the routing rule already implied earlier, a small redundancy that keeps it off a 5.

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 one-parameter read-only alias with no output schema, the description covers purpose, the routing decision, and the returned fields, including what is deliberately missing versus the sibling. Nothing an agent needs to call it correctly is absent.

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 coverage is 100% and the single parameter is documented with examples, so the baseline is met; the description still adds value by stating there is no date argument, which is the key semantic contrast with get_wifi_facts. It does not add further format or validation detail.

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 and resource — a compatibility alias of get_wifi_facts that returns a WiFi answer line for a flight number — and explicitly scopes it to the no-date case. An agent can distinguish it from get_wifi_facts and the other siblings without opening the schema.

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?

Gives an explicit trigger (user wants a quick WiFi answer) plus an explicit precondition (get_wifi_facts not available) and names the default alternative when that precondition fails. Nothing is left to inference.

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