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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is fully covered. The description adds the cost model ('Free') and the scope of what is indexed, which is genuine added context, but says nothing about rate limits, auth, or result staleness semantics.

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?

Two short fragments with zero filler, and the cost signal is front-loaded ahead of the content description. The one-word sentence 'Free.' is terse but earns its place; the style is slightly clipped rather than polished.

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 an output schema present, the description does not need to enumerate return fields, and with no input parameters there is nothing else to document. For a simple status probe it is essentially complete, only missing context on how to act on the freshness data.

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 and the input schema is empty, so there is nothing for the description to disambiguate. Baseline 4 applies for a no-argument tool.

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 names the concrete resources it reports on (the x402 endpoint index and the on-chain ledger) and the two dimensions returned (size and freshness). That is enough for an agent to know this is a status/health read, though it does not explicitly contrast itself with siblings like settled_peek or settled_preflight.

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 leading word 'Free' implies this call costs no credits, which is a usable selection signal against paid siblings, but the description never states when to call it versus settled_preflight or settled_peek, nor any prerequisites. Usage is only implied.

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