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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and openness profile is covered. The description adds value by enumerating the possible status values (complete, in_progress, planned, announced), which tells the agent what vocabulary to expect in results. It says nothing about data freshness or whether a missing airline yields an empty set or an error.

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?

Content is compressed into two clauses with no filler, and the returned data shape is front-loaded ahead of the parameter note. It is dense to the point of reading as a fragment, but nothing is wasted.

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 output schema, the description correctly compensates by listing what is returned (status, fleet percentage, expected completion). For a single optional filter this is nearly sufficient; the only real gap is the absence of any routing cue to the airline- or flight-level WiFi siblings.

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 schema already documents airline_code as an optional IATA filter with an example. The description goes one step beyond by stating the semantics of omission — no filter returns all tracked airlines — which the schema does not spell out. Only one parameter exists, so this is close to full coverage.

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 names the specific resource (Starlink and satellite WiFi rollout progress per aircraft type) and enumerates the returned facets: status, fleet percentage, expected completion. It does not differentiate itself from close siblings like get_airline_wifi or get_wifi_facts, so an agent must infer whether rollout data lives here or there.

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 clause 'Omit airline_code for every tracked airline' gives real guidance on the optional filter's default behavior, which is the main decision an agent faces. However, there is no statement of when to prefer this tool over get_airline_wifi or get_speed_stats, so sibling selection 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.