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

Annotations already declare readOnlyHint and openWorldHint, and the description adds genuinely non-obvious behavior: x402 payment of $0.002 USDC per successful call on Base/Solana/Arc, with failed calls not charged. That is material cost/auth context an agent cannot get from the schema. It still omits pagination depth behavior beyond the declared limits, so not a 5.

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?

Two sentences, front-loaded with what is returned and how to filter, followed by the pricing constraint. The field list is dense but each item is a real attribute of the response; little waste, though the enumeration is longer than strictly necessary given an output schema exists.

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?

Covers source, filters, sort order, pricing/authorization, and charge-on-success semantics; an output schema exists so return values need not be re-explained (the field list is bonus). The unresolved Trade Me vs realestate.co.nz naming is the main completeness gap for an agent deciding whether this is the right NZ source.

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 region values, category options, page/limit ranges are already documented. The description restates the filters and adds only the note that price is 'as advertised' (negotiation/deadline/auction), which concerns output rather than parameter meaning. Baseline 3 applies.

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 concrete verb+resource (property listings search) with a specific, exclusive geography (New Zealand / realestate.co.nz), which separates it from the many other real-estate siblings. The only blemish is that the tool name and title say 'Trade Me Property' while the description names realestate.co.nz as the source, leaving the actual data source slightly ambiguous.

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 clear context: public search, no API key, filtered by region/category/bedrooms, sorted newest first. It does not name an alternative or state when not to use it, so it stops short of full routing guidance, but for a search/list tool the intended use is unambiguous.

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