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

Annotations already declare destructiveHint=true and idempotentHint=false, yet the description adds substantial non-derivable behavior: the +50% per-change / +100% per-24h / -80% cut guardrails, the currency unit convention, and the preview-vs-apply confirm workflow. This is meaningful context an agent cannot infer from the schema or 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?

Three tight sentences, front-loaded with the operation and unit before the guardrails and confirm semantics. Zero filler; every clause carries operative 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?

For a destructive mutation tool with an output schema already covering return values, the description supplies the key invocation-critical facts: currency unit, hard guardrails, and the preview/apply toggle. Nothing essential for a correct call 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?

With 0% schema description coverage, the description carries the burden and does so for the two non-obvious params: it explains budget is in the account's main currency unit (75 = 75.00) and defines confirm's preview/apply semantics. advertiser_id and campaign_id are left to their self-evident names, which is a minor gap.

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?

States a specific verb+resource ('Updates a TikTok campaign budget') that the agent can distinguish from the sibling update_tiktok_adgroup_budget and from the broader set_campaign_budget. The scope (campaign-level, TikTok) is unambiguous from the first clause.

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 confirm=false/confirm=true preview-vs-apply convention gives useful usage context, but no alternative tool is named or contrasted (e.g. set_campaign_budget or update_tiktok_campaign). Usage is implied by the workflow rather than tied to a when-to-use condition.

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