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

Annotations only declare a safe read (readOnlyHint, idempotentHint, non-destructive). The description goes well beyond: image content here is supplemental vs boat_details being canonical, totals must come from customer_cost_summary.full_customer_cost, and deposits are returned separately and excluded from that amount. That is meaningful behavioral context annotations cannot convey.

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 the purpose, then dense workflow guidance with no filler. It is on the long side and packs several distinct topics (IDs, media, extras, totals, deposits, follow-up actions), but each sentence carries actionable information.

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, yet the description surfaces the key return field (customer_cost_summary.full_customer_cost) and the deposit caveat, plus the workflow transition to booking_detail_mod and the final booking/option request. An agent has everything needed to call and act on this tool.

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% so the baseline is 3. The description adds real meaning on top: id_boat and id_tbf1 must be used 'exactly as returned by search_boats,' which constrains their source in a way the schema descriptions do not.

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?

States a specific verb and resource ('Return date-specific availability, pricing, extras and booking choices') and immediately scopes it to 'a selected yacht and charter period.' It distinguishes itself from siblings by name, telling the agent it is not boat_details and that booking_detail_mod handles modifications.

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 alternatives with conditions: do not call for photos, call boat_details with the exact id_boat; after extras/pax/currency/ports/payment change, call booking_detail_mod and use only its server-calculated totals. Both when-to-use and when-not-to-use are covered.

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