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

Annotations already cover the safety profile (readOnly, non-destructive, openWorld), so the bar is lower; the description still adds two valuable traits beyond them: card numbers are never returned (a privacy guarantee stated twice) and an authentication prerequisite ('Cotlet API key with access to this app').

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 content is front-loaded and reasonably tight, but the card-number guarantee is redundantly stated twice ('No card numbers' and 'Card numbers are never returned'), and return fields are listed in two overlapping sentences, costing efficiency.

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 well by enumerating the returned fields (stay dates, room/rate, occupants, comments, notes, invoice lines, payments). Combined with the auth note, an agent has enough to call it correctly; only minor gaps remain.

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% and there is a single documented parameter (reservation_id, with example LH12345), so the schema carries the load. The description adds no syntax or format meaning beyond the schema, warranting the baseline 3.

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+resource ('Get one reservation') and enumerates exactly what the record contains: stay, room, rate, guests, comments, notes, invoice and payments. It is clearly distinguishable from the sibling list_reservations.

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?

Explicitly routes the agent: 'Use it after list_reservations when you need the detail behind one outstanding amount.' It names the alternative and the triggering condition, though it gives no when-not/exclusion guidance.

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