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

Annotations already declare readOnlyHint=false and destructiveHint=true, so safety is covered. The description adds genuinely useful behavioral context beyond that: per-id read-after-write verification and a MAX 25 batch limit. It does not itself explain the preview/confirm token flow, which is left to the schema.

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 verb+resource, then prerequisites, then mode usage, then verification. Dense but every sentence carries information; no filler.

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 is largely sufficient: it covers the modes, limits, keyword_id source, and result verification. The confirm_id preview/confirm requirement is only explained inside the schema rather than the description, 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?

With 50% schema coverage, the description compensates: it tells the agent where keyword_id comes from (ads_list_sb_keywords), explains the single-mode pairing (keyword_id + bid) and the batch shape (items=[{keyword_id, bid}], max 25). account_id/confirm_id are handled by schema descriptions; only profile_id remains unexplained anywhere.

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 (update) and resource (the bid of one or more Sponsored Brands keywords), and the 'Sponsored Brands' qualifier distinguishes it from the SP/SD bid siblings without needing to open the schema. The optimization framing ('la leva per OTTIMIZZARE una campagna SB') reinforces the intent.

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 contrasts optimizing bid price against the alternatives of pausing the campaign or choking its budget, and gives the single vs. batch mode selection with a recommendation for batch. It does not name a sibling tool as the explicit alternative (e.g. ads_update_sb_keyword_state), so it stops short of full when-not routing.

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