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

Annotations already cover read-only/idempotent/closed-world, so the description's job is to add context, and it does: PAUSED items are included, device bid adjustments are returned only when non-zero with '-100 excludes that device', url_options are omitted when empty, and money is in account currency in major units. It does not cover auth/permission requirements or failure behavior, so not a 5.

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?

Opens with the essential scope statement, so it is front-loaded correctly, but the middle is a dense single-sentence enumeration of every returned field. That enumeration has real value given there is no output schema, yet it reads as a wall of text rather than being structured.

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 and a closed-world read tool, the description carries the return-shape burden itself and does so thoroughly, enumerating the snapshot fields, include semantics, dependency rules, and units. Nothing an agent needs to call it correctly is missing.

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 100%, yet the description still adds material meaning beyond the schema: it documents the four selectable sections, the default composition (ad_groups, keywords, ads, without assets), and the undocumented-in-schema dependency that 'keywords and ads require ad_groups'.

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 ('Returns the full configuration snapshot of one campaign') and immediately scopes it with '(no metrics)', which cleanly separates it from performance-oriented siblings like get_device_performance or get_search_terms, and from the list-shaped get_campaigns.

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 clear usage contexts ('Use it to inspect, copy or verify a campaign') and spells out the include semantics, defaults, and the dependency that keywords and ads require ad_groups. It stops short of explicitly naming an alternative (e.g. get_campaign_draft) for the related use case, so a 4 rather than a 5.

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