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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent, open-world mutation, so the safety profile is covered. The description adds useful scope context by naming the UI surfaces affected (dates, buttons, calendar labels), but it omits whether the setting persists, whether it applies to content already authored, and whether sibling pages inherit it.

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?

Two short sentences with no filler, and the effect statement is front-loaded before the value list. The grammar of the first sentence is broken, slightly costing readability, but nothing is redundant.

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 two-parameter setter with no output schema and annotations that already establish the mutation profile, the description covers the value domain and the visible effect. The remaining gap is the ambiguous action verb and the unstated scope/persistence of the setting.

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 50%: the page parameter is documented in the schema, while the language enum has no per-value description. The description compensates by mapping each code to a language name, which is the only added meaning and is largely self-evident for values like en or fr; it says nothing further about the page parameter or its "home" default.

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 explains what the language controls (widget dates, buttons, labels, calendars) and enumerates the accepted values, which lets an agent infer the resource. However, the operative verb is garbled ("Language widgets use for dates and labels") and it never plainly states that it sets the language for a page or subpage, so an agent must lean on the title to confirm the action.

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 explicit when-to-use guidance and no reference to any sibling tool such as list_pages, even though the schema's page parameter depends on list_pages slugs. Nothing says whether this changes only the given page, all pages, or the site default, nor whether it should be called before or after theme/page edits.

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