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

Goes well past the annotations (readOnly/openWorld/idempotent), disclosing that a pasted link triggers a live fetch of up to ~20 seconds, that every returned URL is held or found rather than constructed, and a full taxonomy of `confidence` values with what each does and does not prove. This is exactly the kind of mutation-free but open-world, latency-bearing behavior an agent needs flagged.

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 with the core purpose in the first sentence, then layered detail on confidence, latency, and fallbacks; nothing is pure filler. It is dense and long, and the confidence-enum tour could be trimmed since the output schema already enumerates them, but each sentence still carries decision-relevant meaning.

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 four-parameter, open-world lookup with an output schema, the description covers the things the schema cannot: the none-case semantics, the meaning of matchScore, the absence of booking links on possible matches, and the live-fetch cost. An agent has everything needed to invoke it and to interpret a weak or empty result correctly.

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; the description adds some value by explaining that a URL is matched on its listing id and that `place` never affects matching. However, its '(most reliable)' parenthetical attached to city reads ambiguously against the schema's claim that otaUrl is the most reliable input, which slightly muddies rather than clarifies parameter choice.

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 ('Look up one named property and every way it can be booked, including the host's or manager's own site') and immediately scopes it apart from sibling searches ('a lookup about one property, not a ranked search'). An agent can distinguish this from search_vacation_rentals, get_property, and get_listing_details without opening any schema.

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 concrete input recipes — propertyName plus city, or a listing URL matched on listing id — and says when the answer is 'none' what the fallback lists mean. It frames the tool negatively against ranked search but never names the sibling tools (get_property, get_listing_details) that an agent might confuse it with, so the routing guidance is strong but not complete.

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