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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered by structured data. The description adds genuinely new behavioral context beyond that: it is a paid operation costing 5 prepaid credits and requiring production billing. It stops short of describing what is returned (counts vs. percentages vs. per-status labels), which matters for a classification tool with no output schema.

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 no filler; the core function is front-loaded and the billing constraint follows. Nothing is redundant, though the abrupt cost line would read better as a clearly separated constraint.

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 read-only, single-parameter tool, the description covers purpose and cost, and annotations cover the safety profile. However, with no output schema and no documented return structure, an agent cannot anticipate the response shape of a classification call, which is a meaningful omission relative to the tool's simplicity.

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% and the sole parameter is typed only as a bare array, so the description carries the burden of explaining the input. It does specify that the statuses are 'sampled' and that classification is by success/client/server error, which is meaningful context for what the array should contain. It still does not state the element type (numeric codes vs. strings) or whether input order/length matters, leaving a noticeable gap.

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 uses a specific verb ('Classify') on a specific resource ('sampled HTTP statuses') and names the output buckets (success, client, server errors), so an agent can tell what it produces. It does not reference any sibling, but the sibling list is a broad catalog of unrelated analyzers, so explicit differentiation is not the main gap.

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?

There is no statement of when to use this versus another tool, no prerequisite, and no exclusion. The only conditional information is the billing notice ('PAID ONLY: 5 prepaid credits; production billing required'), which is a cost gate rather than usage guidance.

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