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

With readOnlyHint=true already covering the safety profile, the description adds useful operational context by stating 'No key needed' and that it should be read once before the first preflight_check. It does not describe return format, but for a zero-parameter reference tool this is adequate.

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?

Two tight sentences front-load the tool's purpose and then provide usage timing. Every phrase adds distinct value without 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?

For a simple overview/reference tool with no input schema and no output schema, the description is complete: it states what the reference covers, when to read it, and that no key is required. An agent has enough information to call it 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?

The tool takes zero parameters, so there are no parameter semantics to clarify. The baseline for a zero-parameter tool is 4, and the description correctly does not invent payload fields.

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 this is the reference for Overwing Preflight and enumerates its scope: policy fields, reason codes, verdict promises, price, and guarantee. It distinguishes itself from preflight_check by instructing the agent to read it once before the first preflight_check call.

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 clear usage condition: 'Read it once before the first preflight_check.' It also notes 'No key needed,' which helps the agent understand auth requirements, but it does not explicitly state when not to use this overview or name alternative documentation tools.

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