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

The annotations already declare readOnlyHint, openWorldHint, and destructiveHint=false, so safety behavior is covered. The description adds useful behavioral context about the returned forecast components, confidence calibration, RBF flag, and data source, though it does not mention the L402 payment flow in the description itself.

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 front-loaded and information-dense, with each major clause describing a relevant output or behavior. The opening phrase is somewhat vague, and the long list is dense, but it generally earns its length.

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 tool with no output schema, the description does a good job enumerating return values and the source of the data. Parameters and safety annotations are well covered, though the omission of sibling differentiation and the L402 flow in the description leaves a small gap.

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 all three parameters are already well documented in the input schema. The description reinforces the target fee and forecast window concepts but adds little parameter syntax or meaning beyond what the schema 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 clearly states that the tool returns a Bitcoin fee/congestion forecast, recommended send window, fee trajectory, confirmation targets, and RBF viability. It distinguishes itself as a synthesis layer above raw fee data, but it does not explicitly differentiate itself from the sibling btc_send_decision tool.

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 implies usage by saying this is the decision an autonomous payment agent needs before broadcasting. However, it gives no explicit when-to-use guidance, exclusions, or comparison with alternatives such as btc_send_decision.

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