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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds genuine value beyond that by disclosing the fetch-and-composite behavior (live mempool + fee data) and the concrete output shape (verdict, sat/vB rates, mempool pressure, estimated savings).

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?

Three sentences, front-loaded with the core purpose, then behavior, then audience fit. No filler; every sentence carries 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?

With readOnly annotations and no output schema, the description adequately explains what the agent receives (verdict values, fee rates, mempool pressure, savings). The one missing element is routing guidance against the sibling `optimal_send_window`.

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% and the single `urgency` enum is fully documented with per-value meanings in the schema. The description adds nothing about the parameter, so the baseline 3 for schema-driven params applies.

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?

States a specific verb+resource: returns a composited send-or-wait recommendation for a Bitcoin transaction, and enumerates the verdict outputs. It is clear on its own, but it never distinguishes itself from the sibling `optimal_send_window`, which sounds like an overlapping recommendation 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?

"Ideal for agents that need a single decision call instead of parsing multiple raw mempool endpoints" gives an implied use context. But there is no explicit when-to-use vs. when-not guidance, and the closely related sibling `optimal_send_window` is never named as an alternative.

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