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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered. The description adds genuinely non-structured behavioral context: a free-sample quota per day and a $0.005 USDC per-call charge via x402, which an agent must know before invoking repeatedly.

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 the resource enumeration and the geographic scope. The payment sentence is a compact, useful addendum rather than filler; no sentence is wasted.

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?

An output schema exists, so return-value documentation is not required. Given the annotations carry safety and the description carries cost/quota and geographic scope, the remaining omission (whether all layers are returned together, and the optional-parameter behavior) is minor.

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 nominally 100%, but the schema descriptions are bare labels ('Latitude', 'Postcode', 'Longitude') and 0 parameters are required, so the schema does not clarify whether any one of them suffices. The description only adds the 'at a location (England)' scope hint and does not explain input format or precedence among the three parameters, 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?

The description names the concrete resource set (listed building, conservation area, Article 4, TPO, green belt, AONB, national park) and scopes it geographically to England. It is distinguishable from the single-dataset uk-planning__* siblings (e.g. uk-planning__green-belt, uk-planning__conservation-area) because it aggregates many layers, though it never explicitly says 'aggregate' or names those siblings.

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 bundled tool versus the granular uk-planning__* dataset tools, and no prerequisites for the input (which of postcode/latitude/longitude is needed). The only usage-adjacent statement is the pricing/rate-limit note, which is about cost, not selection.

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