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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds real value by enumerating the response payload (status, daily limit, business hours, stage counts, date-window results) for a tool with no output schema, though it says nothing about permissions or result-size limits.

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 front-loaded sentence with the scope ('one campaign') stated first and the field list following the colon; no filler. The enumeration is long but each item conveys what the caller will receive.

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 simple read-only, two-parameter lookup, the description covers both the required input source and the shape of the return value, which matters since there is no output schema. The only meaningful omission is how it relates to the overlapping targeting sibling.

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%, so both parameters are already documented, including the default-30-day window for 'days' and the campaign_id source. The description restates the default window without adding format or edge-case detail, 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 ('Show one campaign') and enumerates the returned fields, which cleanly separates it from the bulk list_campaigns. It never names a sibling explicitly, so differentiation is inferred from 'one campaign' 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?

No when-to-use or when-not guidance is given. The description does not address the overlap with get_campaign_targeting, which is listed as a sibling and covers one of the same fields ('targeting'), leaving the agent to guess which tool to call.

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