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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety bar is low. The description still adds real value with 'newest first' ordering and the explicit 'never sends or schedules a campaign' disclaimer, which preempts an agent worried that a campaign tool might trigger delivery. It does not discuss pagination or result caps beyond the schema.

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?

One compact sentence plus a short safety clause; the resource and ordering are front-loaded and nothing is wasted.

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?

An output schema exists, so explaining return values in depth is unnecessary; the description nonetheless previews fields, and both optional filters are covered by the schema. Adequate for a simple two-parameter read tool, though it could note result limits at a behavioral level.

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% — both limit (1-200, default 50) and the status enum are fully documented in the schema. The description adds no filtering or syntax 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 the resource (email campaigns), the scope (this workspace), the ordering (newest first), and the fields returned. No sibling tool in the list covers campaigns, so there is no ambiguity to resolve, and an agent knows exactly what this yields.

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 rather than stated: an agent infers this is the read path for campaigns, and the closing clause rules out send/schedule behavior. However, it never says when to prefer this over e.g. list_automations or how to follow up, so no explicit routing guidance exists.

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