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

Annotations already declare read-only, idempotent, non-destructive and closed-world, but the description adds genuinely new context: it does not count toward the allowance, and nothing is purchased by the tool or by opening a link (payment happens on Stripe). It also discloses the current-plan marking and recommendation logic. Return format is left to the 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?

Purpose is front-loaded in the first clause and every subsequent sentence carries non-redundant information about side effects and recommendation behavior. The prose is dense and clause-heavy, which costs some readability, but there is little waste.

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, return values need not be explained; the description still covers the key ambiguities an agent would face: no purchase occurs, links only open the portal, current-plan marking, and how refusal reasons drive recommendations. Nothing needed for correct invocation is missing.

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, but the description adds meaning beyond the schema by explaining the interaction: reason supplies a non-most-recent refusal code, and a known refusal or supplied reason triggers a recommendation of the smallest fixing item. That relational context is not derivable from the enum alone.

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 a specific verb (List) and resource (Pulse Verity plans, prepaid call packs, extra stream connections) with scope (limits, prices, portal links). It is unmistakably distinct from the sibling tools, which all concern index data, prints, or account status.

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 gives clear conditional usage: when a recent plan refusal is known or a reason code is supplied, the smallest fixing item is recommended, which tells the agent when and how to call it. It stops short of explicit when-not guidance or naming an alternative, but no sibling competes for this purpose.

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