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

Annotations already declare readOnly, idempotent, non-destructive and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavior by naming the return payload (self-contained short answer, check date, URL) and confirming the closed Payotte-only corpus, which matters because there is no output schema.

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?

One dense sentence with the geographic scope front-loaded and zero filler; every clause (domain, retrieval action, return contents) carries information.

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 usefully enumerates the returned fields, and annotations cover safety, so an agent has what it needs to call this. It omits the no-match/empty-result behavior and gives no hint about result granularity, which keeps it short of a 5.

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?

Only one parameter and schema description coverage is 100%, so the schema already explains that 'query' takes a question or keywords with examples. The description adds no syntax, format, or length guidance beyond that, so 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 specific verb and resource ('Finds the Payotte guide answering a question') plus the topical scope (buying, financing, selling, renting, owning a home in the UK). The 'UNITED KINGDOM.' prefix separates it from guide_au and guide_in, but it does not differentiate against topically overlapping UK siblings such as house_prices_uk or purchase_tax_uk.

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?

Usage is implied: reach for this when a user asks a UK home-buying/owning question that a short editorial answer would satisfy. There is no explicit when-not, no mention of alternatives (e.g. use purchase_tax_uk for tax figures), and no guidance on how to phrase the query.

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