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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: it is a pre-send pricing operation that computes specific monetary values, including a fixed payout rate of ₦2/contact. No contradictions with annotations.

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 sentences with zero filler. The first sentence front-loads the purpose and the exact return values, and the second gives a precise call-order instruction. Every word contributes useful information.

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 one documented parameter, annotations covering safety and idempotency, and a description that enumerates all four return values, nothing essential is missing. The explicit reference to the send sibling completes the workflow context.

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 schema already documents campaignId at 100% coverage as the UUID of the draft SMS campaign. The description reinforces that the campaign should be a draft, but adds no new parameter-level detail beyond what the schema provides. Baseline 3 is appropriate.

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 ('Price') with a clear resource ('a draft SMS campaign') and enumerates the exact return values: recipient count, SMS provider cost, curated owner payout, and total in kobo. It clearly distinguishes itself from the related send tool by framing this as the pre-send estimation step.

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 description explicitly says 'Call this before neuron_send_sms_campaign,' naming the exact sibling tool and the sequencing. This leaves no ambiguity about when to use this estimate tool versus sending the campaign.

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