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

The description discloses a real behavioral trait beyond the annotations: 5 prepaid credits and required production billing, which an agent needs to know before calling. Annotations already cover read-only and non-open-world, but nothing is said about what the breach output looks like or how partial data is handled.

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 sentences, with the computational purpose front-loaded ahead of the billing caveat. No filler, though the capitalized billing sentence is flatly appended rather than integrated.

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 no output schema, no annotation detail on results, and three undocumented parameters, the definition should say more about the returned budget/breach values and input semantics. As written an agent cannot confidently construct valid inputs or know what it gets back.

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 0%, so the description must carry the parameter explanation and largely fails to. It implies healthy/total are probe counts feeding availability, but never states units, whether healthy must be <= total, or what target_pct expresses.

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?

Contains a specific verb and resource: 'Calculate availability error budget and breaches from uptime probes.' This separates it from the latency-oriented and generic-uptime siblings by naming availability and error budget explicitly, though it does not name the sibling it is not (e.g. privi_pro_latency_slo).

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 'from uptime probes' phrasing implies the input context (probe-derived healthy/total counts), and the PAID ONLY note signals a cost gate. But there is no explicit when-to-use versus privi_uptime_calculate or privi_slo_budget, and no stated prerequisites beyond billing.

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