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

The annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is covered structurally. The description still adds real behavioral context beyond them: the changed-descending ordering, the field inventory, editUrl as an app deep link, and the notable quirk that clicks are hidden below 10 deliveries. It stops short of stating page-size defaults (that lives in the schema) or what an empty result looks like.

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?

It is front-loaded with the 'Read only' signal and has no filler sentences, but the middle is a long comma-run enumeration of return fields, which duplicates the output schema that already exists. That enumeration crowds out the guidance (sibling differentiation) that would have been more valuable.

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 an output schema present and full annotation coverage, the description is complete enough to call the tool correctly: read-only, paginate via nextCursor, filter by kind/status. The main remaining gap is not clarifying how it differs from postfjord_list_email_automations, and the field list is redundant given the output schema.

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 kind, status, limit and cursor are already fully documented in the input schema. The description only restates the cursor round-trip ('Pass nextCursor back as cursor for more'), adding the pagination flow but no new filter semantics. Baseline 3 is appropriate when the schema carries the parameter burden.

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 states a specific resource and scope: email campaigns plus automation emails, sorted most recently changed first, with the fields it returns. It is clear what the tool retrieves, but it never acknowledges the sibling postfjord_list_email_automations, so the boundary between listing campaign/automation emails and listing automation definitions is left for the agent to infer.

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: the agent can gather this is for browsing/filtering emails by kind and status, and the closing sentence explains the cursor loop. There is no explicit when-to-use or when-not-to-use guidance and no named alternative for the adjacent automation-listing tools.

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