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

With no annotations, the description carries the burden. It discloses payment terms, HTTP 402 behavior, that payments are final and non-refundable, and that article text is untrusted data. It also describes return format and dedup behavior. Slight gap: no mention of rate limits or auth, but overall strong transparency.

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 lengthy but all content is relevant. It front-loads the core purpose, then details return format, usage guidance, and payment. The two-part structure (payment disclaimer and provider content) is clear, though slightly verbose.

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 fetch tool with 4 parameters and no output schema, the description covers purpose, return format, parameters' meaning, usage boundaries, payment, and security caveats. Nothing critical is missing for an agent to call it correctly.

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%, so baseline is 3. The description adds value by explaining query types (brand, competitor, person, exact phrase), dedup behavior, and locale availability, which enriches understanding beyond the schema's basic field 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+resource: 'Current Google News coverage for one topic query' and returns normalized rows. It clearly identifies the tool's function and contrasts it with web search and render tools, making its scope unambiguous.

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?

Explicitly says when to use: 'The fastest way to answer what is the news about X right now' and when not: 'for stories older than the RSS window use a web search tool instead; for JS-rendered SPAs use a render tool.' Also notes deduping for multiple queries, giving clear usage context.

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