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

Annotations already cover the safety profile (readOnly, idempotent, openWorld, non-destructive), and the description adds genuinely non-structured behavior: assignment publishing horizon (~2 days out), the fact that assignments can change via aircraft swap, and the extra latency incurred versus calling the predictor directly. That is real operational context beyond the annotations.

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 trigger is front-loaded and each sentence carries distinct information (trigger, return semantics, swap caveat, alternative routing). It is dense and slightly long for a four-field lookup, but no sentence is filler.

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 carries the burden of explaining return values and does so exhaustively, including the no-assignment-yet probability case. Combined with the swap caveat and the sibling routing, an agent has everything needed to call and interpret it.

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 100%, so the schema already documents date format, origin/destination leg-scoping, and flight-number forms. The description adds only the framing that the flight number should be a 'tracked-airline' and marketing number, which is largely reinforced by the schema examples, so baseline 3 is appropriate.

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 and goes further by enumerating the exact return vocabulary (YES, LIKELY YES, NO, probability estimate). It distinguishes itself from the sibling predict_flight_starlink by declaring the fall-through relationship, so an agent can tell them apart without opening either 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 ('Use when the user asks "does my flight have Starlink/WiFi?" with a specific tracked-airline flight number and date') and names the alternative (predict_flight_starlink) with the selecting condition (dates further out, where check_flight only adds latency). When-to-use, when-not, and the alternative are all present.

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