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

The annotations already declare readOnlyHint=true and openWorldHint=false, correctly framing this as a safe local computation. The description adds useful context beyond that: the 12% flat fee mechanic, an effective date (Oct 29, 2026), and that rates are expressed as decimals. It does not describe what the returned structure contains or what happens when inputs are omitted.

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?

It is a single, front-loaded sentence with no filler, leading with the result (new prices) and the fee rationale. The trailing parenthetical date and the decimal note are compact and earn their place, though the sentence packs several distinct facts together.

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 six-parameter compute tool with zero required parameters and no output schema, the description should clarify expected inputs and results. It conveys the fee model and unit format but leaves the return shape and the behavior of omitted parameters unexplained.

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%, so the schema already documents all six parameters, including the pass/absorb modes and the old_rate fee schedule. The description only echoes the covered fields and adds the decimal-unit convention, so the baseline 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 resource (Vrbo nightly, cleaning, and pet prices) and the transformation applied (grossing up to preserve host take-home after Vrbo's flat 12% fee). The 'Vrbo' scope also implicitly separates it from the Airbnb-oriented sibling airbnb_host_only. However, it is phrased as a noun phrase ('New ... prices') rather than an explicit verb, and it never names a sibling it is not.

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?

There is no explicit when-to-use, when-not-to-use, or alternative-tool guidance. Usage is only implied by the intent clause 'keep host take-home the same after Vrbo's flat 12% fee,' and the pass/absorb choice is documented in the schema's mode parameter rather than the description.

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