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

Annotations only declare read-only/non-destructive/closed-world; the description adds substantially more: the quote is non-binding and may diverge from checkout when no date is given, per-date rate-card resolution (weekday/weekend/holiday/operator override), and the discountPreview error code for request-only operators. It also discloses what booking does under each instantBook value, including that nothing is charged until operator acceptance.

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?

Front-loaded with purpose and every sentence carries information; the date-versus-tier and instantBook explanations genuinely earn their space. It is delivered as one dense paragraph without internal structure, which makes the embedded conditional rules harder to scan than they need to be.

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?

No output schema exists, and the description compensates by enumerating return fields (currency, totalCents, depositCents, balanceCents, pricingModel, instantBook, discountPreview) and explaining instantBook's meaning. For a 7-parameter pricing tool this is complete enough to call correctly and interpret the result.

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?

With 0% schema description coverage the description carries the full burden, and it explains the date format and the date-vs-pricingTierId tradeoff plus the captainSlug/boatId exclusivity. It does not clarify what durationId represents (a duration option id?) or the semantics of partySize (guest count, capacity validation), leaving two required parameters thinly specified.

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?

Opens with a specific verb and resource plus scope: "Get a non-binding price quote (in cents) for a charter or rental." The non-binding qualifier and the charter/rental scope distinguish it immediately from create_booking and check_availability without opening any schema.

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?

Gives explicit selection rules: exactly one of captainSlug or boatId, date when known otherwise pricingTierId, partnerCode optional. It also routes downstream behavior (instantBook true → create_booking / create_boat_rental) and states the exclusion that partnerCode cannot be used on request-style operators.

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