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

Annotations already cover the safety profile (readOnly, openWorld, non-destructive), and the description adds genuine operational context on top: a 250 requests/day and 5/minute quota, the underlying lookup window limit, and the from_date workaround. This is exactly the kind of cost/limit disclosure an agent needs before calling.

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?

Three dense sentences, front-loaded with the resource and identifiers before limits and rate cost. Every clause carries information the agent cannot get from schema or annotations.

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 compensates by enumerating the returned record's contents (rooms, daily prices, extras, payments, guest/billing details, next_states). Combined with quota and lookup-window caveats, nothing needed to call it correctly is missing.

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, but the description still adds meaning: it explains that reservation_number takes either the hr_number form or the channel's code, and that from_date exists to reach past a lookup window. It does not restate formats already in the schema.

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 ('One reservation') and names both identifier forms accepted (HotelRunner hr_number or the channel's own code), plus enumerates the payload. It is distinguishable from hotelrunner_list_reservations by its singular scope, though it never names that sibling 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?

Gives a concrete conditional rule that matters: if the reservation predates HotelRunner's lookup window, pass from_date. It stops short of routing the agent between this tool, list_reservations, and get_transaction_details, so no explicit exclusions or alternatives are stated.

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