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

Annotations already declare destructiveHint=true and readOnlyHint=false, and the description adds real behavioral context beyond them: the preview/confirm_id write flow, read-after-write verification per placement or per id, the MAX 25 batch limit, and the guarantee that existing audience segments are preserved. It stops short of stating irreversible effects or rollback semantics, so it is strong but not exhaustive.

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 and packed with genuinely useful detail, but it is delivered as one long run-on paragraph with no sentence breaks, mixing single-path syntax, batch shape, limits and workflow into a single block. Information density is high but parseability suffers.

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-parameter, nested-object mutation tool with no output schema and 50% schema coverage, the description covers everything an agent needs: the two invocation modes, parameter syntax, enum vocabularies, batch cap, confirmation handshake, and the scope boundary against the audience-bidding sibling.

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%, and the description compensates heavily: it supplies the placement enum values and their aliases (top/rest_of_search/product_page/business), the 0-900 percentage range, and the daily_budget→v3 budget{budgetType:DAILY,budget} conversion that the schema does not express. account_id/profile_id/confirm_id semantics are left to 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?

Opens with a specific verb+resource ('Aggiorna una o PIÙ campagne SP') and immediately distinguishes the single-campaign path from the batch path. It also explicitly names the sibling it must not be confused with ('usa ads_update_sp_audience_bidding') and the excluded concern (audience segments).

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 an explicit end-to-end flow (execute_sql on fact_campaign_placement_daily → ads_list_sp_campaigns → before/after preview → confirm → this tool), states when to prefer BATCH ('consigliato per agire su più campagne'), and states what NOT to use it for. Routing is unambiguous.

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