get_user_preferences

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful context beyond that — that the returned values are largely internal UI state rather than meaningful information — but says nothing about scoping (whose preferences), freshness, or defaults for missing preferences.

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, front-loaded with the purpose and followed by the important caveat. Nothing is redundant, though the caveat could have been folded into a single tighter sentence.

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?

With an output schema present and zero input parameters, the description need not explain return values or arguments. It covers what the tool fetches and warns about the low value of the payload, which is the main thing an agent needs before calling it.

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?

The tool takes zero parameters, so there is nothing to document and the baseline of 4 applies. The description correctly implies it operates on the calling account implicitly rather than requiring an identifier.

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?

States a specific verb and resource ("Get this account's Moodle user preferences"), which is unambiguous on its own. It does not name or distinguish itself from the closest sibling, get_user_profile, but the resource noun is distinct enough that an agent can differentiate.

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 note that most values are internal UI state implies a soft "probably don't bother" signal, which is a form of usage guidance. However there is no explicit when-to-use, no prerequisites, and no named alternative for agents seeking meaningful profile/settings data.

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