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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: pricing comes from the same booking preview as booking_detail, the refundable deposit is always reported separately, and missing length/beam values are omitted rather than estimated.

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 parameter bullets are front-loaded and each sentence carries information; the second paragraph is dense but every claim (cost breakdown, deposit separation, cabin labels, missing-value handling) is substantive rather than filler.

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?

With an output schema present, return values need not be fully described, yet the description still explains how customer_cost_summary partitions charter price, extras, full cost and deposit, and how cabin fields are labeled. Combined with the parameter and behavioral notes, an agent has everything needed 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 description coverage is 0%, so the description must carry the parameter burden, and it does: it states the 2..4 boat_ids cardinality (absent from the schema's array definition), the pax meaning, the currency enum EUR/USD/CNY with default, and the YYYY-MM-DD format for start_date/end_date.

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 opening sentence names a specific verb ('Compare') and resource ('boats'), and constrains the scope to 2-4 boats using Sedna's date-specific customer pricing. It clearly differs from siblings like search_boats and boat_details, though it never names those alternatives 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?

Usage is implied by the parameter list: use it when you have 2-4 boat ids and a pax count and want a dated price comparison. However, there is no explicit 'use this instead of X when Y' guidance and no stated prerequisites or exclusions relative to search_boats or boat_details.

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