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

Annotations already declare readOnly, idempotent, non-destructive behavior in a closed world, so the safety profile is fully covered. The description does add genuinely useful behavior beyond that: prices are pre-verified by Rotate, a check date accompanies them, free alternatives are included, and unsupported exams degrade gracefully into an explanatory message instead of an error or fabrication. With no output schema, it still doesn't describe the comparison's structure, so this is solid but not complete.

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 sentences, front-loaded with what the tool returns, followed by the coverage caveat. Every clause carries information: what's compared, the freshness signal, and the fallback behavior.

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-parameter read tool with full annotations and no output schema, the description covers what comes back (prices, contents, check date, free alternatives) and how unsupported exams are handled. Only the shape of the comparison output is left unstated, which is a minor gap.

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% and the enum documents all five exam codes with their FAA abbreviations, so the baseline is already high. The description adds real meaning beyond the schema by distinguishing enum-valid values (all five) from values with actual verified data (part107 and ppl), which an agent cannot learn from the enum alone.

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 names a specific verb and resource: side-by-side prices and contents of prep options for a given FAA exam, plus the price-check date and free alternatives. It implicitly separates itself from single-offer siblings like get_offer and start_checkout through the 'side-by-side' comparison framing, though it never names an alternative tool explicitly.

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 clear applicability boundaries: only verified competitor prices exist, currently part107 and ppl, and other exams return an explanation rather than guessed data. What's missing is explicit routing language telling the agent when to prefer this over get_offer or exam_facts.

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