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

With no annotations, the description carries the full burden and discloses key behaviors: unpaid requests return HTTP 402, a valid X-PAYMENT header makes the same URL return JSON, and pricing is per call/mode. It also explains pagination semantics (newest vs older chunk). This is substantively transparent for a simple endpoint, though rate limits and response schema are not discussed.

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?

The description is a single dense paragraph that mixes payment address, pricing, behavior, and pagination. Each sentence carries information, but the purpose is not front-loaded—the payment address appears first. The structure could be improved with separation of concerns, though it is not bloated or redundant.

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?

The tool has 5 parameters, no output schema, and no annotations. The description covers payment, auth, error handling, and pagination modes, but it omits any detail about the JSON response structure (beyond saying it returns JSON) and does not explain how a valid X-PAYMENT value is obtained. For a paid API with no output schema, these are meaningful gaps that leave an agent partially guessing about downstream processing.

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 the baseline is 3. The description adds value beyond the schema by associating each parameter with cost and pagination direction: id costs $0.02, before fetches the next older chunk, and since provides a watermark. This helps an agent reason about which parameter combination achieves the desired result.

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 clearly states the resource: 'Ofwat Water Industry Act 1991 enforcement-notice text' and the primary verb GET. It distinguishes this tool from siblings (ofgem-enforcement, orr-enforcement) by naming the specific regulator and statute. Despite the payment clutter, the core purpose is immediately identifiable.

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?

The description gives explicit guidance for each access mode: plain GET for the newest chunk, ?before for older chunks, ?since for texts newer than a watermark, and ?id for a single official text. It does not name sibling tools as alternatives, but the regulator-specific scope makes the selection context clear. No exclusions are provided, but the usage context is strong.

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