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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds substantial context beyond them: results are limited to ~2 days out, reflect a published aircraft assignment rather than a prediction, and can still change due to an aircraft swap. That caveat is exactly the kind of reliability nuance an agent needs and annotations cannot express.

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?

Three tightly packed sentences with the use case front-loaded and the routing advice last. Every sentence carries information, though the parenthetical about origin/destination and the assignment caveat make it denser than strictly necessary for a 3-parameter lookup.

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?

There is no output schema, yet the description explains what the results represent (near-term flights with Starlink-assigned aircraft) and their reliability, plus the time horizon and the fallback tools. An agent has everything needed to call and interpret this correctly.

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%, so the three parameters are already documented and the baseline would be 3. The description adds genuinely new semantics: the schema marks zero required parameters, yet the description tells the agent that at least one of origin/destination must be supplied and that supplying both narrows to a single route.

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 states a specific verb and resource (search scheduled Starlink flights) and immediately bounds the scope: near-term departures within ~2 days where the assigned aircraft is Starlink-equipped. It explicitly names the sibling tools to use for other cases, so an agent can separate it from predict_route_starlink and plan_starlink_itinerary without inspecting schemas.

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 concrete trigger phrase ('what Starlink flights leave from X tomorrow?'), states the input constraint (at least one of origin or destination), and gives explicit when-not guidance with named alternatives for later dates. Nothing about tool 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.