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

Annotations already declare read-only, idempotent, non-destructive and closed-world behavior, so the safety profile is covered. The description adds genuinely useful behavioral detail: the default returns key figures while supplying a topic returns everything including gaps and their reasons, and it enumerates the fields each figure carries (period, publication date, rank, comparisons, source, link).

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, zero filler, and the core scope (published figures for one UK area) is front-loaded before the mode split and the field inventory. The second sentence earns its length by compensating for the absent output schema.

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 annotations covering safety, a fully documented schema and no output schema, the description sensibly supplies the return shape and the default/topic mode behavior. The remaining gap is the absence of routing guidance against the six siblings, which an agent comparing similar tools would benefit from.

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 both parameters are fully documented in the schema, which sets the baseline at 3. The description adds the default behavior when topic is omitted, which the schema does not state, but its topic wording ('gaps and their reasons') largely duplicates the schema text, so the net gain over structured data is modest.

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: retrieving published figures for one UK area, with the default (key figures) and the expanded mode (every figure in one topic) both named. It distinguishes scope from siblings like compare_places and get_ranking by emphasizing a single area, though it never names an alternative 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?

Usage is implied through the default-vs-topic distinction ('key figures by default, or every figure in one topic'), which tells the agent how to widen scope. However, there is no guidance on when to prefer this over compare_places, get_ranking, or search_places, so the alternative-selection burden is left to inference.

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