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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is covered. The description adds real value beyond that: it discloses that url_expansion_opt_out will be rejected with an explanatory error, and that passing '' is the destructive removal path. It stops short of describing auth requirements or the full mutation scope.

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?

Three sentences, front-loaded with the primary action, then the deprecation caveat, then the workspace note. Each part earns its place, though the middle sentence is dense and slightly convoluted; bullet-style structure would read cleaner.

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?

An output schema exists, so return values needn't be explained. For a targeted single-field mutation the description covers the key semantics, the deprecation behavior, and workspace scoping. Only minor gaps remain (campaign_id meaning, success behavior), which the schema largely covers.

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 description coverage, the description must compensate, and it does for three of four params: final_url_suffix ('' removes it), url_expansion_opt_out (deprecated/rejected), and workspace (slug, optional when a single workspace). Only campaign_id is left unexplained, but it is self-evident as the required target identifier.

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?

The description states a specific verb (setzen) and resource (final_url_suffix einer Kampagne), narrowing the generic 'Update campaign settings' title to one concrete field. It effectively distinguishes itself from sibling update tools (name, budget, status, bidding_strategy) by field focus, though it never names those siblings explicitly.

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?

It conveys useful usage context: '' removes the suffix, and url_expansion_opt_out is unsupported and should be handled in the Google Ads UI instead. However, it never states when to choose this tool versus the many sibling campaign-update tools, leaving routing to inference from the field name.

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