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 the shape of the payload (status plus sent/replies/bounce stats) and that results are paginated and filterable — meaningful since no output schema exists.

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 tight sentences with no filler: the payload content comes first, followed by the filtering/pagination capability. Every clause maps to something an agent needs.

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 four-parameter, optional-only list tool with full schema coverage and a relevant annotation set, this is close to sufficient — it says what the list contains and how it can be narrowed. The only minor gap is that return ordering and whether the stats are aggregate totals per campaign are left unstated.

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%, with page size defaults, max limits, and the status enum all documented in the schema itself. The description only restates that pagination and status/folder filtering exist, so it does not add meaning beyond the structured fields.

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 names a specific verb and resource ("Lists cold email campaigns") and scopes it to the workspace, plus what each entry carries (status, sent, replies, bounces). It is not explicitly differentiated from siblings like list_leads or list_replies, but the resource noun is unambiguous.

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?

Usage is implied by the resource: fetch campaigns when you need campaign status or performance. There is no explicit when-to-use versus alternatives (e.g., list_campaigns vs. a single-campaign getter), and no stated preconditions.

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