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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows it is a safe, non-mutating operation. The description adds meaningful context by listing the returned fields (gate, delay, baggage, scheduled vs estimated) and clarifying it applies to a single flight. No contradiction with annotations; the added detail goes beyond what annotations alone provide.

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 plus a compact example, with the core purpose front-loaded. Every word earns its place—no fluff, no redundant phrasing. The example is concise and illustrative without bloat.

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 single-flight status tool with no output schema, the description adequately covers the return values (scheduled vs estimated, gate, terminal, baggage claim) and the required inputs. It could mention error behavior or time zone assumptions, but given the tool's simplicity and the schema's completeness, it is sufficiently complete for an agent 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?

Schema coverage is 100% with each parameter having a description, so the baseline is 3. The description adds a full example call that demonstrates how to construct the request, which is mildly helpful beyond the schema. However, it does not provide additional syntax or semantics that are not already in the schema, so 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?

The description states a specific verb ('Returns operational status') and a precise resource (one flight identified by carrier + number + date). It explicitly distinguishes itself from sibling tools by emphasizing 'for one specific flight', which differentiates it from flightstats_airport_status and flightstats_schedule. The example call further clarifies the exact operation.

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 clearly implies when to use this tool (for a single flight status) and provides a concrete example. It does not explicitly name alternatives or state 'use flightstats_schedule for multiple flights', but the scope is unambiguous from the text. No misleading guidance is present.

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