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

With no annotations provided, the description carries the full behavioral disclosure burden. It discloses the pricing model, network, auth requirements, the two-call payment protocol, live probing at request time, the exact output contents and ordering, and the irreversibility of history loss. This is far more transparent than a minimal description.

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 five sentences, and each one carries distinct value: purpose, pricing/auth model, payment flow, return data shape, and temporal limitation. It is front-loaded with the purpose and contains no filler, repetition, or promotional language.

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?

There is no output schema and no annotations, so the description must explain both invocation and return semantics. It does: payment requirements, live probe behavior, retained history ordering, uptime percentage, observed-day count, and transition details. Combined with a fully documented input schema, this is complete enough for an agent to call the tool correctly.

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 coverage is 100%, so the baseline is 3. The description restates the payment workflow already present in the payment parameter schema and adds no new meaning for the `id` parameter. It adds only contextual framing around the payment flow, not new parameter semantics.

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 opens by naming the exact resource: liveness attestation and retained probe history for one endpoint. It then specifies what is returned, including the live probe, full probe series, uptime percentage, observed-day count, and transitions. This clearly distinguishes it from the sibling tools, which are about alerts, trust scores, profiles, search, and bulk export.

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 provides clear invocation guidance: call without `payment` to receive payment requirements, then call again with `payment` to be served, and warns that history cannot be reconstructed after the fact. It does not explicitly name alternative sibling tools or exclusion conditions, but the one-endpoint scope and temporal warning give strong contextual guidance for selection.

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