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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint, so the safety profile is covered. The description adds a small behavioral detail ('pacing airports... read live'), but otherwise does not disclose caching, freshness, or response characteristics beyond what the annotations and output schema imply.

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?

A single, densely packed sentence that leads with the tool's function and then enumerates the five topics. No filler, no redundancy.

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 explanation is not needed, and the description covers all five topic domains that the single parameter can select. Only marginal gaps around freshness/pagination, minor for a reference lookup.

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% and the enum is fully documented in the schema itself; the description's topic list largely restates that enum. Baseline 3 is appropriate since the schema carries the parameter semantics.

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 (decode) and a specific resource (the vocabulary/types used by the faa_delays tool family), and enumerates the domains covered. It is clearly distinguishable from the fetching siblings like get_advisory or list_active_events, since this is a lookup/reference tool, not a data-retrieval one.

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?

Implies the usage context strongly: use this to interpret the codes and terms returned by the other faa_delays tools, and names those tools. It does not give explicit when-not guidance or spell out prerequisites, but the routing intent is clear.

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