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

Annotations already declare readOnly, idempotent, non-destructive, closed-world. The description adds genuine behavior not in the annotations: 31 locales, fallback to 'en' on unknown locale, and that the response reports which locale was served. It does not mention caching or pagination, but nothing suggests those apply.

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 sentences, zero filler, with the resource and locale scoping front-loaded and the fallback caveat immediately after. Every clause earns its place.

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 no-required-param read tool with no output schema, the description covers what the tool returns, the locale contract, the fallback behavior, and a usage rationale. Nothing an agent needs to invoke it correctly 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 description coverage is 0%, so the description must carry the locale semantics — and it does, specifying 31 supported locales, the default/fallback to 'en', and that the served locale is echoed back. This meaningfully exceeds what the bare 'locale: string, default en' schema conveys.

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 (Return) and resource (FAQ entries from the public /faq page), plus the scoping dimension (requested locale). No sibling tool overlaps with FAQ retrieval, so the agent can identify it immediately.

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?

Provides a clear use context: 'grounding answers to common product questions.' It stops short of explicit when-not-to-use guidance or naming alternatives, but for a single-purpose lookup tool the intended usage is unambiguous.

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