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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is well-covered. The description adds the useful caveat that 'These scores do not establish causality' — a meaningful behavioral disambiguation. However, it doesn't explain pagination (cursor) behavior, which is a notable operational trait, but the output schema likely covers return structure.

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 with zero filler. The causality caveat earns its place as a behavioral guardrail. It's appropriately sized for a read-only scoring tool. Could arguably add a brief note about pagination but isn't bloated.

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?

With an output schema present, strong annotations (readOnly, idempotent), and a single required parameter, the description covers the essential context. The causality disclaimer adds important nuance. For a tool whose schema and annotations already carry substantial structured information, this is adequately complete. The only minor gap is absence of guidance on how scores relate to the news feed tools.

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%. The description adds no parameter-specific meaning beyond what exists in the schema — the key term 'scores' for symbols is in the schema. Cursor behavior ('Omit it for the first page') is documented in the schema. The description contributes nothing beyond the schema's parameter documentation, aligning with the baseline 3 for high coverage.

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 uses a specific verb ('Return') with a clear resource ('generated direction, importance, and confidence scores for recent news about selected tickers'). It distinguishes itself from news article lookups (news_article, news_stock) by focusing on computed impact scores rather than articles themselves. The 'generated' qualifier is useful. However, it doesn't explicitly name an alternative tool for comparison, and 'recent news' is somewhat vague.

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 implies usage context (querying news impact scores for tickers) but gives no explicit when-to-use vs alternatives guidance. Among siblings, news_stock and news_article likely return the underlying news, while this tool returns derived scores, but the description doesn't state this distinction. No exclusions or prerequisites are mentioned, and the lookback window (hours) is only in the schema.

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