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

Annotations already cover read-only, idempotent, non-destructive behavior, so the bar is lower, yet the description adds real substance: the previous period is auto-derived (not supplied), and new/inactive destinations appear with previous_period:null or zeroed values with negative change. That edge-case disclosure is genuinely useful. It does not discuss pagination or row limits.

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?

Markdown headings keep it scannable and the Overview is front-loaded with the core concept. It is slightly padded - 'Quick Start' largely restates what the Overview and 'What You Get' already convey - but nothing is confusing.

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 no output schema, the description carries the return-value burden, and the 'What You Get' section enumerates period metadata, summary totals, and per-destination metrics including null handling. That is sufficient for correct invocation and interpretation; row caps and ordering are the only omissions.

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 baseline is 3, but the description adds meaning beyond the schema by stating that from/to define the current period and that the API derives the matching previous period, plus noting sandbox is a query parameter. This tells the agent why there is no previous-period argument.

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 in the Overview ('Returns analytics on destinations') and defines the key scope: destination = hotel country, current vs previous equal-length period. It is clearly separable from siblings like get_bookings_hotels_sales_report or get_bookings_guest_nationality_report by its destination-country focus, though it never names those siblings 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?

The 'When to Use' section gives four concrete scenarios (destination performance, period comparison, geographic dashboards, inventory planning), which is strong context. It stops short of explicit when-not-to-use guidance or naming the alternative report tools an agent should pick instead.

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