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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds only that results are 'current' and that only one public section is returned per call, with no mention of result volume, ordering, or pagination.

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 sentence with no waste; the resource is front-loaded and the constraint follows immediately. Nothing could be trimmed without losing information.

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 structure needn't be explained, and the single parameter is fully documented with annotations covering safety. Only minor gaps remain (how many headlines are returned, ordering/freshness guarantees).

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 enumerates the documented section slugs, so the baseline is 3. The description adds genuine meaning beyond the schema by constraining the value's provenance to marketwatch_sections, which the schema does not express.

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 verb+resource ('Current MarketWatch headlines') and scopes it to 'one public section', which is concrete. It implicitly separates itself from marketwatch_news and points at marketwatch_sections, but never explicitly contrasts with the sibling news tool.

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 states an explicit prerequisite: the section value 'must come from marketwatch_sections', telling the agent to call that tool first. It stops short of saying when to prefer this over marketwatch_news or marketwatch_article.

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