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

Annotations already declare readOnlyHint=false, destructiveHint=true and openWorldHint=true, so the mutation risk is covered. The description adds the 25-item batch cap and 'Esito verificato per-id', but never discloses the two-step preview/confirm write flow that the confirm_id parameter implies, nor rate/limit behavior beyond the batch cap. Useful, but not rich for a destructive write.

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 core action, then the sibling routing, then the two usage modes with their payload shapes. Capitalized keywords (SINGOLA/BATCH/MAX 25) make it scannable. Slightly telegraphic with abbreviations, but no sentence is wasted.

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 6-param destructive mutation with no output schema, it covers the essentials: what is changed, how to source target_id, single vs batch limits, and per-id result verification. The preview/confirm contract and the account_id/profile_id scoping are left entirely to schema field descriptions, which is a minor gap.

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 50% (bid, target_id and profile_id are undocumented in the schema), and the description compensates: it explains that target_id comes from ads_list_sp_targets, that batch items each carry their own bid, and that bid applies to MANUAL targets or AUTO groups. It does not clarify the optionality/role of account_id, profile_id or the single-vs-batch mutual exclusion.

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?

Specific verb+resource: updates the bid for one or more SP targets, and explicitly enumerates the target kinds covered (MANUAL ASIN/category and the four AUTO groups). It also names the sibling it is NOT (ads_create_*) and the sibling that supplies target_id (ads_list_sp_targets), so an agent can distinguish it from ads_update_sp_target_state and the create family without opening schemas.

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?

States both execution modes and when to pick each: single (target_id + bid) vs BATCH (recommended when many targets, each with a different bid, MAX 25). It routes the agent to ads_list_sp_targets for target_id and explicitly rules out ads_create_* for modulating auto-group bids on an existing AUTO campaign.

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