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

Annotations already declare readOnly/showWorld/non-destructive, so the bar is lower; the description adds pagination semantics (cursor round-trip) and the auth requirement (Cotlet API key with access to this app), which are genuinely beyond the structured fields. It could say more about default page size or sorting, but the added context is solid.

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 and mostly efficient, but the opening sentence and 'Each customer comes with addresses and a booking count' restate the same field list, wasting a sentence. The 'BookingKoala:' prefix adds no 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?

For a read-only list tool with no output schema, it covers the essentials: return fields, pagination, auth, and how the ID feeds other tools. Only minor gaps remain (default page size, ordering), which are not critical for correct invocation.

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 limit/query/cursor are already documented in the schema. The description echoes the query semantics ('by name, email or phone') and cursor behavior but adds nothing for limit. 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?

States a specific verb and resource ('Lists customers, or searches them by name, email or phone') and enumerates the returned fields (name, email, phone, addresses, booking count). An agent understands exactly what the tool returns and can distinguish it from sibling list tools like list_bookings or list_invoices.

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 clear usage context: pass query to search, use customer_id downstream with list_bookings or create_booking, and pass next_cursor back as cursor. It never states when-not to use it, but for a read-only listing tool there's little risk in that omission.

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