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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safe read-only nature is known. The description adds that results are short Q&A pairs and authoritative, which gives a hint about response character, but discloses nothing about filtering behavior, pagination, or any other runtime trait beyond what is obvious.

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 with zero extraneous content. The primary action and output format are front-loaded, followed by a compact list of covered topics and a single, useful use-case 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?

For a simple, read-only FAQ lookup with one optional parameter and no output schema, the description covers the output format, topical scope, and when to use it. The only minor gap is that the description does not explicitly mention the topic parameter's filtering capability, but the schema fully covers that, so nothing critical 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 100% and the single parameter has an enum with its own description ('Return only entries on this topic.'). The tool description mentions some topics (privacy, requirements, cost) but does not map them precisely to the enum values (privacy, requirements, pricing, comparison, developers), so it adds no meaningful semantics beyond the schema.

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 ('Get'), a concrete resource ('the Yappy FAQ'), and a clear output format ('question and answer pairs'). It also enumerates topical coverage (privacy, requirements, cost, permissions, offline use, comparison), making the tool's scope immediately understandable. The contrast with 'a documentation page' further sharpens the purpose.

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 description gives a clear usage context: 'Useful when you want a short authoritative answer rather than a documentation page.' This tells an agent when the tool is appropriate relative to documentation retrieval, but it does not explicitly name sibling tools or state when not to use alternatives like get_pricing_plans or get_system_requirements.

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