get_index_history

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

Annotations already declare readOnlyHint, destructiveHint, idempotentHint, making the safety profile clear. The description adds that the tool returns historical closing prices and market breadth, but does not detail other behavioral traits (e.g., data frequency, default days). No contradiction with annotations.

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 two sentences (English + Vietnamese) and front-loaded with key information. It is concise with no wasted words. The bilingual redundancy is minor.

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?

Given no output schema and two simple parameters, the description is adequate but lacks detail on what 'market breadth' includes or the response format. A bit more context would help disambiguate from sibling 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?

Input schema has 100% coverage with descriptions for both parameters (index values and days max 365). The description adds minimal value beyond the schema, essentially restating the indices. Baseline 3 is appropriate.

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 provides historical closing prices and market breadth for VNINDEX, VN30, and HNX indices. It uses specific verbs and resources ('historical closing prices + market breadth'), distinguishing it from siblings like get_price_history (stock-level) and get_market_snapshot (current snapshot).

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 for index historical data but offers no explicit guidance on when to use this tool versus alternatives (e.g., get_price_history for stocks). No exclusions or conditions are provided.

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