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

Annotations already declare readOnly, idempotent and open-world, so safety is covered. The description adds real behavioral context beyond them: approximate volume (~3,500), the ~7-day retention window, newest-first ordering, and the quirk that one release can appear once per language — a duplication trap an agent would otherwise hit.

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 dense sentences, zero filler, with the temporal scope and multilingual caveat front-loaded where an agent will see them before deciding to call.

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?

No output schema exists, but the description enumerates the returned fields (headline, dateline, language, published time, excerpt, release id) and the ordering, so an agent knows exactly what comes back from this zero-required-parameter read 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 coverage is 100%, so limit, language and since_hours are already fully documented, including the 168-hour window and per-language duplication. The description's 'Pass language "en"' tip largely restates the schema's own language note, adding marginal value over structured data.

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+resource (latest press releases) and pins the exact source: Business Wire's all-news RSS channel. It explicitly contrasts this scope with the full archive, letting an agent distinguish it from businesswire_search_releases and businesswire_get_release without opening a 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?

Gives a clear selection signal — the ~7-day / ~3,500-release window bounds what the tool can answer, and 'Pass language "en" for English only' is actionable. It never names the archive-search sibling as the alternative for older items, so the when-not guidance is implied rather than explicit.

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