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

readOnlyHint=true already tells the agent this is a safe read. The description adds real value by revealing the return shape (signed URLs plus summary metrics and strategy IDs), but stays silent on the traits that actually matter for signed URLs: expiry, whether they are publicly accessible, and cost of regenerating them.

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?

A single front-loaded sentence with no filler; the return content comes first and the enumeration follows. It is efficient but too terse for a 5-parameter tool with zero schema documentation.

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 summarizes what comes back (URLs, metrics, strategy IDs), which is the main thing an agent needs. However, for a 5-parameter tool at 0% schema coverage it omits the semantics of the four include* flags and the required backtestId, leaving the call contract under-specified.

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 0%, so every one of the 5 parameters is undocumented. The description names tearsheet/trades/indicators/stats as outputs rather than explaining that includeTearsheet/includeTrades/includeIndicators/includeStats are toggle flags defaulting to true, and it never mentions backtestId being required.

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 gives a specific verb ("Returns") and a precise resource ("signed URLs for visual backtest artifacts"), enumerating the artifact types in parentheses. It is clearly distinguishable from write operations, but it never names near-siblings like get_backtest_artifact, get_backtest_chart_series, or get_strategy_visuals, so the agent must infer the boundary.

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?

There is no statement of when to use this instead of get_backtest_artifact, get_backtest_chart_series, or get_strategy_visuals, and no prerequisites such as the backtest needing to be finished. The agent is left to guess the selection criteria entirely.

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