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

Annotations already declare readOnlyHint=false, destructiveHint=true, openWorldHint=true, so the write/destructive profile is covered. The description adds substantive context beyond that: the batch cap (MAX 25) and that outcomes are verified per-id, which tells the agent the call can partially succeed. It omits mention of the preview/confirm (confirm_id) two-step write flow, but the schema documents that.

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?

Front-loaded with the action, then the alternatives, then the identifier source, then the single vs batch calling convention. Dense and mostly waste-free, though the heavy capitalization and mid-sentence abbreviation ('SB') add mild parsing friction.

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 calling modes, batch limit, and per-id result semantics, which substitutes for the missing return documentation. The main gap is that the preview/confirm write protocol is only implicit via the schema's confirm_id.

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 50%, so the description must carry the mutual-exclusion logic, and it does: SINGOLA = target_id + bid, BATCH = items=[{target_id, bid}] with MAX 25, plus the origin of target_id. account_id, confirm_id, and profile_id are left to the schema, which does describe account_id and confirm_id.

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 precise verb+resource ('Aggiorna il BID di uno o PIÙ product target Sponsored Brands') and explicitly distinguishes itself from the sibling ads_update_sb_keyword_bid and from the placement multipliers in ads_update_sb_campaign, as well as implicitly from the SP counterpart ads_update_sp_target_bid. An agent can route correctly without opening any schema.

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?

Explicitly names the alternatives (keyword bid tool, campaign placement multipliers) and gives the strategic condition for choosing this tool over pausing/cutting budget. It also names the prerequisite source for the identifier ('target_id da ads_list_sb_targets'), so the agent knows the required upstream call.

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