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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and external data are covered. The description adds that it returns headline items from a public feed, but does not disclose pagination, rate limits, or update frequency. Without such added context, it remains at the baseline.

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?

Three concise sentences, each adding distinct value: first states what it does, then provides alternatives for related tasks. No redundancy.

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 that there are no parameters, annotations cover safety, and an output schema exists (so return values needn't be described), the description provides all necessary context for correct invocation and sibling selection.

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?

The tool takes no parameters, so there is nothing to describe; the description appropriately avoids parameter discussion. Baseline for zero parameters is 4.

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 it fetches Investopedia top stories from the public feed and returns headline items from the general top-story stream. It distinguishes itself from siblings by explicitly naming investopedia_headlines for section-specific lists and investopedia_article for single articles.

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?

It gives explicit when-to-use: for general top stories, use this tool; for section-specific, use investopedia_headlines; to discover sections, use investopedia_sections; and for article bodies, use investopedia_article. This is comprehensive routing guidance.

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