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

Annotations already establish destructive=true/readOnly=false, and the description adds meaningful behavior: invalid max_cpc combinations 'return an error instead of being silently ignored' (error semantics) and confirm=false performs a dry-run. It does not mention permissions/auth scope, but the error and dry-run disclosures go beyond the structured fields.

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 purpose followed by a dense but well-organized per-strategy spec; the max_cpc constraint paragraph is long but essential and prevents a real invocation error. Every sentence carries operational weight, though the run-on caveat sentence could be tightened.

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?

Given 7 strategy variants, 9 parameters and conditional requirements, plus an output schema that handles return values, the description covers strategy selection, dry-run behavior, and error handling. An agent has what it needs to invoke 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?

With 0% schema coverage the description carries the full burden and largely succeeds: it maps each strategy to required/optional params, gives a units example (3.5 = 350%), and lists the impression_share_location enum values. Only customer_id and campaign_id remain unexplained, which is a minor gap.

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 ('Changes a campaign's bidding strategy') and enumerates the exact strategy values with their required/optional parameters. It explicitly distinguishes itself from the portfolio sibling by noting it 'cannot create or assign' a PORTFOLIO/shared strategy, so an agent can separate it from manage_portfolio_bidding_strategy.

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?

Usage is implied through the per-strategy parameter requirements and the portfolio caveat, but there is no explicit 'use this when X, otherwise use Y' routing versus manage_portfolio_bidding_strategy or manage_campaign_settings. The confirm=false dry-run hint is a useful operational cue but is not a when-to-use guideline.

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