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

Annotations only declare this is a non-destructive, non-open-world write. The description adds genuinely new behavioral facts: it never accepts credentials, creation happens in the host with its approval prompts, webhook triggers are stored by the owner in Zipline Settings, and "Registration is not verification" warns the registration does not confirm the routine works.

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?

Purpose is front-loaded and each subsequent sentence adds a constraint (prerequisite read, host approval, credential prohibition, webhook alternative, verification caveat). It is dense but not padded; the closing caveat is terse and earns its place.

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 mutating registration tool, the description covers prerequisites, the credential/auth boundary, the mode-dependent alternative path, and the limits of what registration proves. The only gap is that it never says what a successful registration returns, and there is no output schema to fall back on.

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 0%, so the description must carry parameter meaning. It maps routine_id ("real ID") and host ("host name") and gestures at interval_minutes via "cadence," but never explains the five mode enum values, which mode requires interval_minutes, or the minute units and 10080 bound.

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?

"Record a routine the user has already created in their host, so Zipline can notify it when addressed messages arrive" states a specific verb, resource, and effect. No sibling tool is a near-duplicate, so no explicit differentiation is needed, though it does reference get_connection_status as a prerequisite.

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?

It gives a concrete sequence: read wake-up opt-in and schedule_preferences from get_connection_status, follow the host's own approval prompts, then register. It also splits behavior by mode, noting that webhook modes reuse a trigger the owner saves in Zipline Settings, Automations. Missing only an explicit 'do not call when...' exclusion.

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