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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description goes beyond that by disclosing structural semantics of the result — ordering, inclusion of A/B variants, and that delayDays is measured from the previous step with the first step at 0 — which an agent needs to interpret the data correctly. It does not mention pagination or permissions, which is minor for a read-only, non-open-world call.

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 first states what is returned, the second resolves the one non-obvious detail about delay counting. Both sentences earn their place and the key information is front-loaded.

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 carries the burden of describing return content, and it does so for the important parts: an ordered list of emails, A/B variants, and per-step delayDays semantics. It stops short of enumerating the other fields each step carries, but an agent has enough to call the tool and read the result correctly.

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?

There is a single parameter, and the schema already documents it at 100% coverage, including its origin ('from list_campaigns') and its exclusiveMinimum constraint. The description adds nothing about the id beyond what the schema provides, so the baseline of 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?

The description uses a specific verb and resource ('Returns the ordered emails that make up a campaign's sequence') and adds a scope qualifier about A/B variants. It is clearly a read operation on sequence structure, distinguishing it from replace_campaign_sequence by wording, but it never names that sibling or contrast get_campaign with this tool explicitly.

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 only implied: an agent can infer this is the tool for inspecting a sequence rather than editing it. There is no statement of when to prefer it over get_campaign or get_campaign_stats, and no prerequisites or exclusions are given.

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