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

The annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds the 1-year lookback limit and REST endpoint, but does not disclose return format, pagination, or other behavioral details. This modest addition beyond annotations warrants a 3.

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?

The description is a single, well-structured sentence that front-loads the main function and key constraint. Every word earns its place, with no redundancy or vague language.

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?

This is a simple read-only news lookup with three required parameters and clear annotations. The description covers the essential purpose and date-range limit, which is sufficient for selection. Without an output schema, it could say more about the return structure, but 'news' reasonably implies a list of articles, so a 4 is appropriate.

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 input schema already provides full descriptions for all three parameters (symbol, from, to) with 100% coverage. The description's reference to 'date range' aligns with the schema but adds no new semantic information, so the baseline score of 3 applies.

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 retrieves 'Latest company news for a symbol over a date range', naming the specific resource and operation. It also cites the REST endpoint, and 'for a symbol' distinguishes it from sibling finnhub_market_news which covers market-wide 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 provides useful context (per-symbol, date range, up to 1 year back) but does not explicitly mention when to use this tool versus alternatives like finnhub_market_news. Usage is implied rather than clearly stated, so it meets the 'implied usage' level.

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