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

With no annotations, the description carries the behavioral burden and does well: it discloses the USDC payment requirement, per-request costs, HTTP 402 on unpaid requests, and that the same URL returns JSON after a valid X-PAYMENT. It does not mention rate limits or any non-obvious side effects, but a paid GET is reasonably characterized.

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 compact and dense, front-loading the endpoint and payment requirement before the data-retrieval modes. The telegraphic structure and repeated 'Not a new SKU' are a little cryptic, but every sentence contributes information and nothing is padded.

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?

For a five-parameter tool with no annotations and no output schema, the description covers payment, error behavior, and chunking well, but it never describes the shape of the returned JSON. An agent can start a call, but it cannot predict the response structure or fully understand page vs. before/since behavior from the description alone.

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 reinforces the cost and chunking intent of id, since, and before, but does not add new syntax or format details beyond what the schema already provides.

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 identifies the resource as 'FDA De Novo classification-order text' and states the operation is a GET, which is enough for an agent to tell it apart from the many regulatory-order siblings. However, the core purpose is embedded in a payment/billing sentence rather than a clear 'Retrieve...' statement, and 'Not a new SKU' adds ambiguity about what the tool is for.

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?

It gives clear context for selecting query modes: plain GET for the newest chunk, ?before for the older chunk, ?since for newer-than-watermark, and ?id for one official text. It does not name alternative tools or state exclusions, so it stops short of a full when-to-use vs. siblings explanation.

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