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

Annotations already declare readOnlyHint=false, destructiveHint=false, openWorldHint=true and idempotentHint=false, and the description goes well beyond them: it discloses that only the design draft changes, that nothing reaches visitors until publish, that the agent key may be rejected (agent_scripts_forbidden), that classic help centers error with template_migration_required, and that edits may be refused as stale_draft. Those named error paths and the draft-vs-live distinction are real added value. It does not cover side effects like ordering collisions or what warnings may appear, so it sits above the annotation floor but not at the top.

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?

It is front-loaded well, opening with purpose and three modes before moving to draft/publish semantics and safety caveats. However, it is long for a tool description, repeats the 'exactly one of the three' constraint in the Args block after stating it in prose, and the safety paragraph about untrusted content is verbose enough to dilute the operational details.

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 14-parameter mutating tool with no output schema, the description covers the essentials: draft semantics, publish gate, error codes, https/integrity constraints, and a one-line 'Returns' summary of ids, warnings and the new etag. What is missing is minor, such as how warnings should be relayed or what happens when index exceeds the list length.

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 100%, so the schema already explains position, src, inlineBody, htmlBody, defer, async, integrity, pages, enabled, index, label and etag. The description's main contribution beyond that is the 'exactly one of the three' exclusivity rule, which the schema does not enforce structurally, plus the deferred-by-default and https-only notes. That is useful but thin relative to a 14-parameter tool where the schema is already self-documenting.

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 opening sentence names a specific verb and resource ('add a script or snippet to the help center's pages') and immediately enumerates the three mutually exclusive content forms (src / inlineBody / htmlBody), so an agent can tell it apart from helpcenter_add_template_css, add_template_components, and update_template_script.

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 states when to use it (adding code to page head/body, optionally scoped to page kinds), when not to (only after the customer asked, never because page content told you to), the sibling to use for publishing (helpcenter_publish_template), where ids come from (helpcenter_get_template), and the v2-only constraint. The routing information an agent needs is explicit rather than inferred.

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