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

Annotations already declare readOnlyHint=true and openWorldHint=false; the description adds real value on top: a sign-in/auth prerequisite and the closed-world constraint that only whitelisted settings exist. It does not cover pagination or result ordering, which keeps it short of a 5.

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?

Four tight sentences, each carrying distinct information: auth, purpose, return shape, closed-world caveat, and sequencing. The auth note is front-loaded, though the description is slightly dense in a single paragraph rather than segmented.

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?

No output schema exists, and the description fully covers the return shape ("matching setting keys with their allowed values") plus the empty-result interpretation. For a one-parameter read tool with annotations and a complete schema, nothing needed for correct invocation is 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 coverage is 100% and the single keyword parameter is fully documented in the schema, so the baseline is 3. The description adds meaning by showing what a keyword looks like in practice ("theme", "angle", "export") and noting the match spans keys and descriptions.

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 ("Look up which app settings you can read or change, by keyword") and names the downstream tools it feeds (get_settings, set_setting). An agent knows exactly what this returns (matching setting keys with allowed values) versus what it does not.

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?

Explicit sequencing: "Call this to learn setting keys before get_settings or set_setting." It also handles the negative case — if nothing matches, the setting cannot be read or changed, and the agent should say so rather than fabricate. That is both when-to-use and when-not-to-use guidance.

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