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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description goes further with domain semantics that structured fields do not carry: delayDays is relative to the previous step and the first step is always 0. It omits return format details beyond the basics, but with annotations doing the safety work this is a solid addition.

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 zero filler. The primary return description is front-loaded and the delayDays semantics follow immediately as supporting detail.

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?

There is no output schema, so the description must carry the return contract, and it does communicate the shape (ordered emails, A/B variants included) plus the delayDays convention. It leaves gaps around empty-sequence behavior and whether variant ordering is guaranteed, but it is sufficiently complete for a simple single-parameter read.

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?

Only one parameter and schema description coverage is 100% -- the schema already documents id as 'The numeric campaign ID (from list_campaigns)'. The description adds nothing about the id parameter, so the baseline 3 applies; the schema is fully doing the work here.

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+resource ('Returns the ordered emails that make up a campaign's sequence') and clarifies scope with 'including any A/B variants,' which distinguishes it from get_campaign and replace_campaign_sequence. It stops short of naming those siblings explicitly, so an agent must infer the boundary from the resource noun alone.

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 read-only, inspection-oriented phrasing, but there is no explicit when-to-use statement, no mention of when to prefer get_campaign over this, and no note on prerequisites. The reference to a numeric campaign ID from list_campaigns hints at the retrieval flow without spelling out the routing.

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