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

Beyond the annotations (readOnlyHint, idempotentHint, non-destructive), the description adds that this is a real-time 'snapshot' covering ALL active programs, and that each result includes the delay reason. This provides useful behavioral context about the tool's scope and output content, though it does not disclose response size or potential truncation.

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 description is two sentences, with the first sentence front-loading the core purpose and the second providing concrete use-case examples. Every phrase earns its place, and the inclusion of delay types adds clarity without excessive verbosity.

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 tool with no parameters, strong annotations, and no output schema, the description is sufficiently complete. It communicates the nationwide scope, the types of programs included, the reason field, and gives example queries. The absence of an output schema is compensated by this clear description of the data content.

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?

The tool has zero parameters, so the baseline is 4 as per the rubric. The description appropriately avoids mentioning parameters since there are none, and the schema already fully documents (vacuously) that no parameters are needed.

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 clearly states the tool provides a 'Nationwide snapshot of ALL active FAA delay programs right now' and enumerates the types of delays covered (ground stop, ground delay, arrival/departure delay, closure) including their reasons. This specific verb+resource+scope distinguishes it from the sibling tool 'airport_delays' which likely focuses on a single airport.

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 description explicitly states when to use it with example queries like 'which airports have delays today' and 'are there nationwide ground stops'. It gives clear context for nationwide use cases, though it does not explicitly mention when not to use it or name the alternative 'airport_delays' tool.

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