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

The description adds value beyond annotations: it discloses the daily quota limit, free usage, the returned result format ('structured results immediately'), and scope (100+ languages, 250K+ sources). Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint as false, so the description complements these with operational constraints.

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?

The description is two sentences with no wasted words. It front-loads the purpose, limits, and scope, then immediately provides an alternative tool. Every sentence 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?

Given the low complexity (3 params, no nested objects, no output schema), the description covers the core behavior, limits, and boundaries well. It does not describe the return structure in detail, but since no output schema exists, a brief note on immediate structured results is sufficient. The additional context on languages and sources adds confidence for the agent.

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 67%, and the description does not explicitly detail parameters beyond saying 'first-level search' and mentioning domains. However, the domain parameter's enum values (news, papers) are documented in the schema's description, and the query parameter's purpose is clear from the context. The description could add more syntax details for payer_address, but overall it adds context about the free tier, reducing the need for exhaustive param docs.

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 clearly states the tool performs a 'free first-level search' across two distinct domains (news and scholarly papers), using specific verbs like 'search' and 'returns.' It distinguishes from siblings by naming a9n9_research_quote as the alternative for paid deep research.

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 explicitly tells when to use this tool (current news or arXiv papers) and when not to, by naming a9n9_research_quote for paid deep research when quota is exhausted or live browsing is needed. This provides clear context and an alternative.

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