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

Beyond the readOnly/openWorld annotations, the description discloses that no key is needed, full articles are paywalled and not returned, the exact x402 price per successful call, accepted payment chains, and that failed calls are not charged. These are substantive behavioral details an agent needs before invoking a paid read-only search.

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 four compact sentences, front-loaded with the FT headline purpose, then moves through filtering, content limits, access, and payment. Each sentence carries useful information with no repetition or filler.

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 output schema, read-only/open-world annotations, and full parameter coverage, the description covers the essential context: source, filtering, content limitations, access model, and cost. Nothing critical is missing for an agent to invoke 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% and the schema already describes q, limit, and section. The description reinforces that keywords filter title/summary and that section accepts homepage or section/topic slugs, but it adds little beyond the schema and does not mention the limit parameter.

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 states a specific resource (Financial Times headlines from public FT RSS feeds) and scope (international homepage or any section/topic stream, with keyword filtering). It also distinguishes this tool from other news-search siblings by naming the FT source and limiting output to headlines/standfirsts.

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 clear context that this is for FT headline retrieval, not full articles or general web search, because it mentions the RSS source and paywall limitation. However, it does not explicitly name alternatives or say when to prefer other news search tools.

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