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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds real value by saying what comes back (status plus sent/replies/bounce stats) and that pagination/filtering are supported, which matters because there is no output 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?

Two tight sentences, front-loaded with the primary action and followed by the payload/supporting capabilities. No filler or restated title boilerplate.

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, describing the returned fields (status, sent, replies, bounces) is exactly the missing piece, and it is provided. Minor gaps remain around default sort order and what an empty workspace returns, but the definition is broadly sufficient for a read-only list tool.

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 each of the four parameters (page, limit, status, folderId) is already documented in the schema. The description only echoes the filtering and pagination capability without adding format or default details, 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 ('Lists cold email campaigns in the workspace') and summarizes the returned payload. It distinguishes itself implicitly from get_campaign/get_campaign_stats via the 'Lists' scope, though it never names a sibling explicitly to draw the boundary.

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?

Mentions the supported capabilities (pagination, filtering by status or folder), which implies when to use it, but gives no explicit when-to-use vs when-not, no guidance on choosing list_campaigns over get_campaign or get_campaign_stats, and no prerequisites.

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