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

Annotations declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, but the description adds material context the annotations do not: it touches the live account, the object starts PAUSED and won't spend until activated, and confirm:true is a hard safety gate. That is genuine value beyond the structured hints, though it says nothing about rate limits or 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, each earning its place, with the live-account warning and the default-state behavior front-loaded before the call requirement.

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?

No output schema exists, and the description covers the safety profile, default state and required gate, which is enough for an agent to call it correctly. It could note what the tool returns (e.g. the new campaign id) to be fully complete.

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%, so name, status, objective, daily_budget and confirm are already documented in the schema. The description only restates the confirm gate and the PAUSED default, adding no new semantics such as budget units or objective selection guidance.

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 and resource ('Create a new Meta campaign'), clearly distinguishing it from siblings such as meta_ads_update_campaign or meta_ads_create_ad_set. The bracketed write-scope marker further disambiguates it from the read/list siblings.

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?

Gives operational guidance (created PAUSED, requires confirm:true), which tells the agent how to call it safely, but never says when to choose this over alternatives like meta_ads_create_ad_set or meta_ads_boost_post, nor any prerequisites beyond the confirm gate.

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