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

Annotations already declare readOnlyHint=false and destructiveHint=true, so the safety profile is covered. The description adds real behavioral context beyond that: a hard MAX 25 items per call and read-after-write per-ID verification of the outcome, which the agent would not otherwise know.

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 single-vs-batch pattern and the limit. Dense but every clause 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 covers modes, the batch cap, and result verification. The one notable omission is that the two-step confirm_id write flow is left entirely to the schema, but overall an agent has enough to invoke it correctly.

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%. The description does clarify the two core parameter patterns (keyword_id+bid vs items=[{keyword_id,bid}]) and the 25-item cap, but it omits the preview/confirm flow driven by confirm_id and leaves profile_id/account_id to the schema, so it only partially 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 and resource: updating the bid of one or more SP keywords. It clearly scopes to SP (Sponsored Products) keywords, but does not explicitly route away from the near siblings ads_update_sb_keyword_bid or ads_update_sp_target_bid, so the agent must infer the SP/keyword distinction.

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 strong internal usage guidance: SINGLE mode uses keyword_id + bid, BATCH mode is recommended for many keywords at once and avoids call bursts. It does not, however, state when to prefer a sibling tool or any preconditions/exclusions relative to them.

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