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

Annotations declare destructive/openWorld/non-idempotent, but the description adds the crucial behavior those flags cannot: the two-step confirmation protocol, where a first call mutates nothing and returns a question plus confirmToken to be replayed only after human assent. It also discloses the real-world effect (emails send automatically) and that merchant sign-off happens once per flow.

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?

Front-loaded with the action, then eligibility, then the confirmation handshake — a sensible order. Some phrasing is roundabout ('the people it is for, so the merchant always says yes first, once per flow') and could be tightened, but no sentence is dead weight.

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 destructive, open-world mutation with no output schema, the definition covers what an agent needs: eligibility gates, the side effect outside the product, and exactly what the first and second calls return/require. Nothing material is left unstated.

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 the baseline is 3, but the description goes beyond the schema by constraining which kind values are legal in a given context (no store → welcome only) and by reinforcing that confirmToken is never to be invented. The confirmToken replay rule is partly duplicated from the schema, keeping it out of the top band.

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?

Opens with a specific verb+resource: 'Switch on an automated email flow.' It is clearly distinguished from draftFlow (create), readFlows (read), and updateFlowStep (edit a step) — this is the activation step for an existing flow.

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?

Explicit preconditions and exclusions: flow must be off, business must have the audience, 'without a store, only the welcome flow', and only for workspaces with subscribed email contacts. An agent can decide eligibility without further inference.

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