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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the supported timeframe set, the ≤1000 candle cap, and a prompt-injection warning about {untrusted_text: ...} fields originating from brokers, hooks or people.

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 tight sentences: purpose first, constraints second, security caveat last. Every sentence carries distinct information and nothing is padded.

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 no output schema, the description usefully hints at the return shape via the {untrusted_text: ...} field note and bounds the result size. It does not explain pagination or what happens when start_time is null/absent, leaving a small gap.

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 100%, so the schema already documents limit, symbol, timeframe, account_id and start_time. The description restates the timeframe list and the limit ceiling but adds no format or semantics beyond the schema, so the baseline 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?

States a specific verb+resource (historical OHLCV candles) and names the intended use (technical analysis and indicators like MA/RSI/ATR). This clearly separates it from siblings such as get_quote and get_history, though it never names those siblings explicitly.

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?

Usage is implied by 'for technical analysis and indicators', which signals the analytical context, but there is no explicit when-to-use or when-not-to-use guidance and no routing to alternatives like get_quote or get_history.

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