create_sd_campaigns

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

Without annotations, the description carries the full burden. It labels the tool as a 'guarded write' and notes it is a 'stub', but does not explain what guarded write entails, what happens on execution (e.g., whether it actually creates or just returns a preview), or any side effects. The behavioral traits are insufficiently disclosed.

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?

The description is very concise, consisting of only two sentences. It is front-loaded with the core purpose ('Preview or create Sponsored Display campaigns') followed by a necessary context note about being a stub. Every word serves a purpose with no redundancy.

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 the tool has 5 parameters, no output schema, and no annotations, the description is incomplete. It does not explain the output format, error conditions, or how to interpret the results (e.g., what 'preview' returns vs. what 'create' returns). As a creation tool, more detail is needed for an agent to use it 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?

The input schema has 100% coverage with descriptions for all 5 parameters. The description does not add any additional meaning or context to the parameters beyond what is already in the schema, so it meets the baseline of 3 but does not exceed it.

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 clearly states the tool's purpose: 'Preview or create Sponsored Display campaigns.' It uses specific verbs ('preview', 'create') and a specific resource ('Sponsored Display campaigns'), which distinguishes it from sibling tools like archive_sd_campaigns or create_sd_ad_groups.

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?

The description provides minimal guidance on when to use this tool. It mentions it is a 'hosted endpoint only' and a 'local stdio server is an introspection stub,' which implies limited functionality, but does not explicitly state when to use it vs. alternatives like create_sd_ad_groups or when to preview vs. create. No 'when not to use' or alternative tool references are given.

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