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

Annotations already declare destructiveHint=true, idempotentHint=false and openWorldHint=true, so the safety profile is partly covered. The description earns credit for the non-obvious operational detail that this is a real, billable send counted against the connection's limits, but it says nothing about failure modes, whether the campaign must be in a particular state, or what happens if no SIM is assigned.

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?

It is short and front-loaded with the action, but the inverted phrasing ('the campaign's words, as its first person gets them, from its first SIM') makes the reader work to reconstruct a simple operation. The quota sentence earns its place; the preceding clauses could be plainer.

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 and full parameter coverage, the description only needs to add behavioral context, and it does supply the essential one: this is a real send consumed against limits. It is nearly complete, missing only preconditions such as campaign state or SIM assignment.

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%, and the schema already documents both 'id' (cmp_…) and 'to' (normally the user's own number). The description reinforces that the test goes to one number normally owned by the user, which is mildly useful, but adds no format or syntax detail beyond the schema. Baseline 3 applies.

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 states a specific verb and resource: it texts a campaign's current draft copy, rendered as the first recipient would see it, sent from the campaign's first SIM to a single number. That is clear enough to separate it from send_sms, but it relies on the indirect phrasing 'the campaign's words' rather than naming the draft content explicitly.

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?

'A launch needs a test of the current words' implies the when: preview before launching. However, it never names alternatives such as send_sms or draft_sms, nor states when not to use it (for example, on a paused campaign or one without a provisioned SIM). Usage is implied rather than spelled out.

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