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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description reinforces this with "Read-only." It adds genuinely non-obvious behavior: results are simulated, it renders an interactive panel only in MCP Apps hosts, and it always returns a text summary plus a botspot.trade link — important fallback context absent from the 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?

One dense sentence plus short clarifiers, front-loaded with the user question and the concrete output. Every clause — count limit, chart basis, metric list, simulated disclaimer, read-only, fallback output — 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?

With one parameter, existing annotations, and no output schema, the description covers what an agent needs: input meaning, count bounds, rendered vs. text fallback output, and the simulation caveat. Nothing material is missing.

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 the description carries the burden. It clarifies that the IDs must reference saved backtests and reinforces the 2-5 count, which orients the agent beyond the raw array-of-uuid schema. It does not name the parameter explicitly or describe behavior on invalid/unknown IDs.

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?

Opens with the exact user question it answers and names the resource (2-5 saved backtests), then specifies what it produces: equity lines rebased to 100 on a shared chart plus a metric table. An agent can distinguish it from show_backtest_dashboard or get_backtest_chart_series without opening any schema.

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 framing "Which of my backtests did better?" plus the 2-5 saved-backtest constraint makes the triggering condition clear. It does not explicitly exclude alternatives (e.g. single-backtest views like show_backtest_dashboard), so it stops short of a 5.

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