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

Annotations already declare destructiveHint=true, readOnlyHint=false and openWorldHint=true, so the safety profile is covered. The description adds real information beyond that: the two-step preview/confirm flow for bid-raise and cap-removal operations, plus the fact that amounts are in account currency. It does not state reversibility or what the preview contains, so it falls short of a 5.

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 compact sentences: the operation and scope come first, the risky preview/confirm requirement second. No redundant restatement of the title, no filler, and the most agent-critical constraint (confirm=true) is given prominence.

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, open-world mutation with seven parameters, no output schema and thin schema descriptions, the description covers the essentials: what it changes, the currency unit, and the confirmation gate. Remaining gaps — adset identifier format, what the preview response looks like, and reversibility — are modest but real.

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 only 43% (folder, account, language documented), leaving adset, confirm, bid_amount and bid_strategy bare. The description compensates by explaining the 'and/or' relationship between strategy and amount, that bid_amount is in account currency, and precisely when the otherwise-undocumented confirm flag must be true — meaningful added semantics beyond the schema.

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: 'Set bid strategy and/or bid/cost-cap amount ... on an ad set,' which distinguishes it from the adjacent budget-editing sibling. It stops short of naming meta_update_budget or other siblings, but the bid-vs-budget distinction is unambiguous from the text.

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 conditional 'Raising a bid or removing a cap returns a preview and needs confirm=true' gives an explicit when-to-confirm rule, which is useful guidance. However, there is no when-to-use/when-not guidance relative to alternatives such as meta_update_budget, nor any stated prerequisites (e.g., ad set must exist and use the relevant bid strategy), so usage is only partially framed.

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