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

Beyond the annotations (which only declare non-readOnly, non-destructive, openWorld), the description adds real behavioral traits: it is created PAUSED, nothing is delivered until enrollment plus activation, and it auto-stops for unsubscribers. It also discloses an API limitation (no media) that would otherwise cause silent failures.

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 tightly written sentences: the first front-loads what the tool is and its delivery model, the second packs the paused state, activation requirement, and media limitation. No filler.

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?

For a mutation tool with no output schema, the description covers the lifecycle, enrollment dependency, activation step, and a key limitation, which is nearly everything needed to call it correctly. It does not mention the response shape, though with no output schema declared that is a minor gap.

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 80%, so the schema already carries most parameter meaning (accountId, idempotencyKey, stopIfTheyReply, steps). The description only adds the semantic that each step fires after its delay, which loosely maps to delayMinutes; the baseline 3 is appropriate.

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 (Create) and resource (timed message sequence / drip) plus its scope (for subscribers of one account). It distinguishes itself from the closest sibling by explicitly naming create_broadcast as the tool for media, so an agent can route without opening either schema.

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?

Gives explicit when-to-use context: created PAUSED with nothing sent until contacts are enrolled and it is activated (activate_sequence), and a clear when-not alternative (use a broadcast when media is needed). The lifecycle and the follow-up activation tool are both named.

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