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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds that campaigns are returned with inbox, schedule, and status, but does not disclose pagination, rate limits, authentication needs, or return structure. With annotations carrying the main burden, a 3 is appropriate.

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?

Two tightly written sentences with no redundancy. The purpose is front-loaded followed immediately by the key usage condition, leaving no wasted words.

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?

With no output schema, the description should clarify the return shape, but it only mentions three fields and omits pagination, ordering, or total count. For a list endpoint this is a notable gap, though the annotated safety profile and field hint make it minimally adequate.

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%, so the single 'fields' parameter is fully documented in the schema. The description does not add any syntax or filtering semantics beyond what the schema provides, so the baseline of 3 is correct.

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 (List) and resource (campaigns) with scope (of this account) and some returned fields (inbox, schedule, status). It does not differentiate itself from the sibling get_campaign, which retrieves a single campaign, so a 4 is appropriate rather than a 5.

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?

Explicitly says to call before changing or deleting a campaign, which gives clear context for use. It does not name specific alternatives (e.g., get_campaign for full details) or state when not to use this tool, so it falls short of a 5.

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