Draft a shared negative keyword list

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

Annotations declare readOnlyHint=false and destructiveHint=false, but the description adds the crucial non-obvious trait: this is a deferred write that returns a preview with a plan_id and changes nothing until confirm_and_apply. That resolves ambiguity the safety hints alone would leave (an agent could otherwise assume immediate mutation).

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 scope, then sibling differentiation, then the preview/confirm workflow. Slightly padded by the bare Google Ads API documentation link, which adds little for an agent already inside this toolset.

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 need not be explained, and the description still notes the preview/plan_id shape. Combined with annotations and complete parameter docs, nothing essential to a correct invocation 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 description coverage is 100% and the five parameters are fully documented in the schema (keywords, list_name, match_type, campaign_id, customer_id). The description adds only the conceptual notion of a shared list, no syntax or format 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?

States a specific verb and resource ('Draft a shared negative keyword list') and immediately scopes it against the sibling add_negative_keywords, which adds negatives to one campaign. An agent can distinguish this reusable-shared-set tool from its neighbors without opening any schema.

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?

Names the alternative tool and the exact condition that selects it ('shared set that can later be applied to multiple campaigns' vs 'adds negatives directly to one campaign'). It also states the workflow prerequisite: nothing is applied until confirm_and_apply runs.

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