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

The annotations already declare readOnlyHint=true, so the safe-read profile is covered. The description adds that it returns open date windows and GuestHost booking links, which is useful output context beyond the annotations, but it does not explain any behavioral constraints like rate limits, auth needs, or why only one apartment is covered.

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 description is short, front-loaded with the resource identity, and contains no filler. However, its extreme brevity for a tool with four undocumented parameters makes it feel under-specified rather than carefully concise.

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 tool with four parameters, no output schema, and minimal annotations, the description is incomplete. It does not explain parameter usage, required versus optional inputs, or how the returned date windows should be interpreted, leaving significant gaps for an agent to fill.

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?

With four parameters and 0% schema description coverage, the description carries the full burden of explaining the inputs. It provides no meaning for 'guests', 'arrival', 'departure', or 'destination', leaving all parameters undocumented.

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?

The description identifies a specific resource (a direct-bookable apartment in Milan) and what it returns (open date windows and booking links), but does not state a clear action verb like 'search' or 'list'. The name 'search_stays' suggests a broader search capability than the single-apartment scope described, and it does not differentiate this tool from the sibling 'get_booking_link'.

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?

There is no guidance on when to use this tool versus alternatives such as 'get_booking_link'. It does not mention prerequisites, required parameters, or scenarios that would select it over another tool.

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