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

Annotations only declare readOnlyHint false, but the description adds critical behavior: templates are always created as drafts, content.elements must be wrapped in a channel block or the API rejects it, the response carries a verification object whose semantics are explained, and an unauthorized errorKind still means the template was created. This goes far beyond the annotations and contains no contradictions.

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?

The description is longer than average, but every clause adds essential operational detail: draft status, channel block requirement, verification semantics, unauthorized caveat, and a complete example. It is front-loaded with the purpose before caveats. Slight redundancy with the schema's own examples keeps it from a 5.

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 nested parameters and no output schema, the description covers the non-obvious behaviors an agent must know: creation always draft, verification result meaning, and errorKind semantics. Combined with 100% schema coverage and annotations, nothing critical is left to guesswork.

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 already 100%, but the description adds a complete example, explains the required nesting of elements inside a channel block, and warns to copy journey_id exactly rather than retype it. It also reinforces that state must be DRAFT. This adds meaning beyond the schema's field descriptions.

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 states a specific verb and resource: 'Create a notification template scoped to a journey.' It immediately distinguishes this from siblings like create_notification (not journey-scoped) and create_journey (creates the journey, not the template). The draft-only constraint further clarifies what the tool does and does not do.

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?

The description clearly frames when to use the tool: to create a journey-scoped notification template that is always a draft, and explicitly says making it live is a separate step this tool cannot perform, implicitly pointing to publish_journey_template. It also gives fallback guidance for verification false (re-read journey, do not create a second template). It does not name sibling tools explicitly, so not a 5.

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