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

Annotations only declare readOnlyHint and openWorldHint; the description adds real context beyond them: pricing (0.05 USD per series, paid in USDC via x402) and the fact that calls today return a status payload rather than data. Not disclosing the exact status response shape keeps it from a 5, though with no output schema a hint would help.

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?

"COMING SOON" is front-loaded so the agent cannot miss the availability caveat, and both sentences carry distinct information (what it will do, what it does now, cost). Minor awkwardness in "as we read them" costs a point but nothing is padding.

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 zero-parameter, no-output-schema placeholder, the definition covers availability, cost, intended purpose, and present-day return behavior. The only substantive omission is naming the specific free alternative to route to.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline applies. It correctly implies no inputs are required for the current status-check behavior.

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?

Names the resource (historical funding, costs, and order books, venue by venue) and its intended use (backtesting a strategy), and explicitly distinguishes the current placeholder behavior from the eventual paid product. It is clear about what the tool is for, though the eventual output shape stays abstract.

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?

"Calling it now returns its status and the free tool to use meanwhile" tells the agent this is not yet a data source and that it should fall back to a free sibling. The gap is that it never names which sibling (funding_rates, trading_cost, depth, cost_per_point are all plausible), leaving the agent to guess.

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