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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful behavioral context: results are 'current' (freshness) and limited to 'public' sections, plus the cross-tool validation constraint on the section value.

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 front-loaded sentence with a semicolon clause; no padding. Purpose comes first, the constraint second, both earning their place.

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?

Output schema exists so return values need no explanation, and the read-only annotation covers safety. Purpose, scope, and parameter sourcing are all addressed; only the relationship to marketwatch_news/marketwatch_article is left implicit.

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 0% and the lone 'section' parameter is an unconstrained string, so the description carries the burden. It adds real meaning by telling the agent the value must come from marketwatch_sections and must be a public section, which the schema does not convey.

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 resource ('Current MarketWatch headlines') scoped to 'one public section', and references the sibling marketwatch_sections as the source of valid values. An agent can distinguish it from marketwatch_news and marketwatch_article without opening any schema.

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?

Provides clear context that the section argument must be sourced from marketwatch_sections, effectively a prerequisite for correct invocation. It does not explicitly state when to prefer this over marketwatch_news, so it stops short of full alternative routing.

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