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

Annotations already declare destructiveHint=true and idempotentHint=true, covering the core safety profile. The description adds a meaningful behavioral constraint (draft-only), but does not disclose whether deletion is permanent, whether confirmation is needed, or what happens to associated resources. This is acceptable given annotation coverage, but not exceptional.

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 action is stated first, and the critical constraint is front-loaded in the second sentence. Every word earns its place.

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 single-parameter delete operation with annotations covering destructiveness and idempotency, the description covers the essential precondition (draft status). It does not describe return values or error cases, but no output schema exists and the operation is simple enough that these are not critical gaps.

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 100%, with campaignId already described as 'UUID of the draft SMS campaign to delete.' The description reinforces the draft-only requirement but adds no new parameter semantics beyond the schema. 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 ('Delete') and a specific resource ('draft SMS campaign'), making it clear which operation is performed. It also distinguishes itself from siblings like delete_campaign and pause_sms_campaign by specifying the SMS campaign context and draft state.

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 states a key usage condition: 'Only draft campaigns can be deleted.' This tells the agent when the tool is applicable and prevents attempts on non-draft campaigns. It does not explicitly contrast with alternative tools, but the name and draft qualifier provide adequate differentiation.

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