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

Annotations already establish a safe, idempotent, closed-world read, so the bar is lower; the description adds real value by disclosing the return shape (id, name, type, target CPA/ROAS, CPC ceiling, attached campaigns with status), which matters because there is no output schema. It doesn't cover pagination or result-size limits.

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?

Two dense sentences with the returned-field list and the routing guidance front-loaded; every clause (including the get_campaign_setup exclusion) earns its place.

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?

With no output schema, the description correctly compensates by enumerating return fields, and it closes the main ambiguity risk (portfolio vs. campaign bidding) by pointing elsewhere. An agent has everything needed to select and call it.

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?

Only one parameter, and the schema documents it fully at 100% coverage, including where the customer ID comes from. The description adds no format or origin detail beyond the schema, so the baseline 3 applies.

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?

Specific verb ("Lists") plus a precisely scoped resource ("the account's portfolio (shared) bidding strategies"), and it enumerates the returned fields. It also explicitly distinguishes itself from get_campaign_setup, which covers per-campaign bidding.

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?

States the downstream consumers of the returned id (attach_bidding_strategy and update_bidding_strategy) and names the alternative tool (get_campaign_setup) with the condition that selects it. Nothing is left to inference.

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