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

Annotations only declare a safe read; the description adds substantial behavior beyond that: edits target a DRAFT shared with the dashboard's Template Editor, nothing reaches visitors until helpcenter_publish_template, and v1 centers reject with template_migration_required. That is exactly the context an agent needs and cannot infer from readOnlyHint.

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 core action, and the Args/Returns block mirrors the schema cleanly. The middle paragraph enumerating six page kinds, six regions and theme tokens is informative but long for a listing tool and overlaps ground covered by the template guide tools.

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?

There is no output schema, so the description must explain returns, which it does ("the gallery, or one theme with changed_sections"). Combined with the draft/publish model and the v1 restriction, an agent has everything needed to call this correctly and interpret the result.

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?

With 100% schema coverage the baseline is 3, and the description does add a little meaning — the current theme is marked, and passing `theme` reveals per-page composition plus which sections applying it would change. However, its `theme` sentence closely restates the schema's own parameter text rather than extending it.

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 gives a specific verb and resource plus both modes ("List the ready-made themes a help center can start from, or describe one in full"). It is clearly separable from siblings like helpcenter_get_template and helpcenter_apply_template_theme.

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 the triggering situation ("when the customer wants a new look, or a starting point to customize from") and routes the follow-up action to helpcenter_apply_template_theme. It also gives a hard precondition — only v2 help centers can be edited, v1 returns template_migration_required and migration is the owner's call — which prevents a whole class of misdirected calls.

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