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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is well covered. The description adds that it returns summaries rather than full article text — useful behavioral context. It doesn't mention pagination via cursor or result limits, but with strong annotations covering the safety profile, a 3 is appropriate.

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?

Two concise sentences, zero waste. The description front-loads the core purpose and immediately flags the key limitation (summaries only, not full text). Every word earns its 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?

For a read-only news-fetching tool with a rich output schema and good annotations, the description covers the essentials: what it returns, the scope (one ticker). It could mention the cursor-based pagination pattern or hours/limit defaults, but the output schema and input schema supply much of the remaining context. Adequate but not exhaustive.

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 75%, with symbol having a clear description (Example: AAPL), and hours/limit having self-explanatory descriptions. The cursor parameter is well-documented in the schema ('Omit it for the first page'). The description adds limited param value but the schema already does substantial work for 3 of 4 params. Cursor lacks description-level explanation of pagination semantics, hence 4 rather than 5.

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 'Return recent news summaries for one ticker' — a specific verb+resource+scope. It clearly differentiates from siblings like news_general (general news) and news_article (full articles), and explicitly notes it returns summaries, not full text. Slight deduction because it doesn't explicitly name sibling alternatives, though the 'one ticker' scoping distinguishes it.

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 notes it returns summaries and not full article text, which implicitly guides against using this for full articles. However, it doesn't explicitly state when to use this vs alternative tools like news_article or news_general, nor does it mention required parameters. The 'one ticker' constraint is implied but no explicit exclusions are given.

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