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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds value beyond that by disclosing what the read returns — channels, audiences, ads, and budget configuration — which tells the agent this is the full-detail endpoint rather than a summary view. It stops short of noting whether missing IDs error or return empty.

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?

A single well-formed sentence that front-loads the action and identifier, then lists the payload contents. Nothing is redundant or misplaced.

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?

For a one-parameter read-only getter with full annotation coverage and no output schema, the description is nearly sufficient — it pre-summarizes the returned fields, which compensates for the missing output schema. The only gap is the lack of guidance on error behavior for an invalid or unknown campaign ID.

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?

There is exactly one parameter and schema coverage is 100%, with the schema describing it as 'The wizard campaign ID to retrieve details for'. The description restates this without adding format, range, or source-of-ID guidance, so 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 ('Get') and resource ('campaign details') plus the qualifier 'by its wizard campaign ID', which separates it from the many campaign-related siblings. It does not explicitly name list_wizard_campaigns or search_campaigns_by_names as the enumeration/search counterparts, so sibling differentiation is implied rather than stated.

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 'by wizard campaign ID' framing implies this is for fetching a known campaign rather than discovering one, which is meaningful given siblings like list_wizard_campaigns and search_campaigns_by_names. However, the description never states when to prefer this over those alternatives, and no prerequisites or failure conditions are mentioned.

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