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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds the constraint that sections must be valid values from fortune_sections, which is a real behavioral rule, but says nothing about pagination or currency beyond the word 'current'.

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?

A single lean sentence with the resource and the constraint front-loaded and no wasted words. Appropriately sized for a one-parameter tool.

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?

An output schema exists, so return values need no explanation. With one parameter whose valid values are sourced to fortune_sections, the description is largely complete for such a simple tool.

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 0%, so the description must carry the parameter. It does add meaningful information by naming fortune_sections as the source of valid section values, but it gives no format examples or indication of what a valid section string looks like.

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 (returns) and resource (current Fortune headlines) with a clear scope qualifier ('one public section'). It does not explicitly distinguish itself from siblings like fortune_news or fortune_article, so an agent must infer that 'headlines' means section-fronting headline lists rather than full articles or general news.

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 prerequisite-style pointer ('section must come from fortune_sections') which is genuinely useful routing, but it offers no when-to-use vs. when-not guidance against fortune_news or fortune_article. Usage is only implied.

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