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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the bar is lower; the description still adds the return shape (audience_id, name, description, source), the IT/DE/FR/ES/UK availability, and an anti-hallucination warning about not inventing audience_id. The redundant 'READ-ONLY' opener adds nothing over the annotation.

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-loads the scope and packs source semantics, return fields and routing into a compact block; every sentence carries information. It is dense and slightly run-on, but there is no padding.

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?

No output schema exists, and the description compensates by naming the returned fields plus the downstream tool that consumes them. For a zero-required-parameter list tool with a clear follow-up path, this is close to complete; only the non-documented locale/profile_id parameters remain unexplained.

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?

With 60% schema coverage the description usefully expands the source enum ('amazon' = Amazon-built audiences with concrete examples, 'amc' = Amazon Marketing Cloud, 'all') and confirms search as an optional text filter, adding meaning beyond the bare enum. locale, account_id and profile_id are left to the schema, which only partly compensates.

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+resource ('Elenca i SEGMENTI DI PUBBLICO ... per i moltiplicatori di bid delle campagne Sponsored Products') and scopes it to audience bid adjustments. It is immediately distinguishable from sibling list tools like ads_list_sp_campaigns and ads_list_sp_targets.

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 routes the agent: returned audience_id must be passed to ads_update_sp_audience_bidding, and segments already set on a campaign are read via ads_list_sp_campaigns. It lacks an explicit 'do not use this when...' clause, but the routing context is unusually clear.

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