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

Annotations already declare non-read-only, idempotent, non-destructive, closed-world behavior, so safety is covered. The description adds essentially no behavioral context: it does not say whether unspecified fields are preserved, that status defaults to draft, or what publishing does. The trailing clause "using the page block schema" is confusing for a flat 7-field schema and borders on misleading.

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 a single short sentence with no padding, which is good, but the brevity comes at the cost of substance and the "page block schema" reference is unexplained jargon. Front-loading is fine; the sentence simply does not earn its place given how little it conveys.

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 seven parameters, one required UUID, an enum-backed status field, and zero schema description coverage, the description is far too thin. The output schema is present so return values need not be explained, but field-level meaning and update semantics are missing.

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 0% across seven parameters, so the schema gives no per-field meaning, and the description does not compensate at all. It mentions only generic "copy fields" while headline, subhead, privacyNote, submitLabel, sessionPickerHeading, and the status enum go entirely unexplained.

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 names a verb ("update") and a resource ("simple registration page copy fields"), so the general intent is discernible. However, "copy fields" never enumerates the editable fields, and nothing distinguishes this tool from siblings like update_core_details, update_branding_settings, or update_offer_replay_basics, which are equally plausible candidates for editing registration page content.

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?

There is no statement of when to reach for this tool versus the many other update_* siblings, no prerequisites, and no exclusions. An agent must guess whether this covers layout/blocks, branding, or core details based on the label alone.

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