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

With no annotations, the description carries the full burden, and it does disclose real behavior: unpaid requests return HTTP 402, a valid X-PAYMENT header makes the same URL return JSON, and the x402 payment address/price are given. It stops short of describing what the returned document contains, rate limits, or error behavior beyond 402.

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 URL and price are front-loaded, but the text is cluttered with repeated, near-identical phrasing ('Same door, not a new SKU' / 'Not a new SKU') and scattered price figures. Several clauses restate the payment mechanics rather than adding new 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?

For a paid multi-mode fetch with no output schema, the description covers the payment flow and the query-mode branches adequately, but it omits any note on the shape of the returned JSON or how pagination interacts with since/before beyond the schema. Enough to call it correctly, not enough to call it confidently.

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 schema already documents all five parameters; per the rubric that sets a baseline of 3. The description only adds per-mode pricing ($0.02 for ?id, $0.05 for the rest), which is marginal additional meaning.

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 resource is identifiable (FERC eLibrary Commission order/opinion and ALJ initial-decision text) but it is embedded inside payment boilerplate rather than stated as the tool's job. It does not distinguish itself from the close sibling ferc-orders, so an agent cannot tell from the description alone which to pick.

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 usefully maps query modes to intents: plain GET = newest chunk, ?before = older chunk, ?since = newer than a watermark, ?id = one official text. However, there is no guidance on when to use this tool versus sibling tools like ferc-orders, so cross-tool routing 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.