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

Annotations already flag this as a destructive, non-read-only, open-world mutation, so the bar is lower. The description still adds real behavioral context the annotations cannot: the preview-and-confirm two-step protocol for bid increases and AUTO_BID moves, and the account-currency unit convention for bid values. It stops short of saying whether changes are reversible or what the preview payload contains.

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 sentences, zero filler, front-loaded with what changes and immediately followed by the confirm requirement. The parenthetical units note is dense and earns its space.

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 with no output schema, the description covers the safety-critical part (confirm gating) and the value semantics (currency). Remaining gaps — which fields are required, whether a preview is always returned, and the effect of omitting bid_strategy — are moderate but not blocking for correct invocation.

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%, so the description must carry more weight. It does explain 'bid' (max bid or target cost, in account currency), implies the bid_strategy values via AUTO_BID, and defines the confirm flag's trigger condition — but folder, account, adsquad, and language are left entirely to the schema. Meaningful compensation, but incomplete for seven parameters.

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?

Names a specific verb (change) and a specific resource pair (bid strategy / bid) on an ad squad, and clarifies the units (max bid or target cost, account currency). It is clearly distinct from sibling mutations like snapchat_update_budget or snapchat_update_schedule, though it never explicitly names those 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?

Provides one concrete usage rule — raising a bid or switching to AUTO_BID returns a preview and requires confirm=true — which tells the agent how to complete the two-step flow. However, it gives no guidance on when to prefer this tool over snapchat_update_budget or snapchat_create_adsquad, and no exclusions or 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.