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

Annotations give readOnlyHint=false with destructiveHint=false, which is potentially confusing, and the description usefully resolves it: the tool writes an approval artifact but 'never mutates TikTok'. It also adds the 'bounded tenant-owned' scope and the single-use nature of the returned reference. It omits auth requirements, idempotency behavior, and validation failure modes.

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?

Three short sentences with the core behavior front-loaded and zero filler. Phrasing like 'bounded tenant-owned' is slightly opaque jargon, but nothing is wasted or buried.

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?

The description conveys the essential model (validate, no mutation, return approval_ref), which partially compensates for the absent output schema. However, for a tool with 7 required parameters and no schema descriptions, leaving nearly every input unexplained is a real gap.

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% across 8 parameters, so the description must carry the burden, yet it clarifies only entity_type (ad_group vs adset alias). run_id, rule_id_and_version, idempotency_key, entity_refs, target_status, ad_account_id, and connection_context are left entirely unexplained.

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 and resource ('Validate a ... TikTok delivery-status change') and states the artifact produced ('return a single-use approval_ref'). It also separates itself from the confirm counterpart via 'This tool never mutates TikTok', though it never explicitly names the delivery_status_confirm sibling as the downstream 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 only routing guidance is parameter-level ('Use native ad_group; adset remains an explicit adapter alias'), which addresses enum choice rather than when to call this tool instead of delivery_status_confirm or bid_prepare/budget_prepare. The prepare-then-confirm relationship is only implied by the name.

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