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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, covering the safety profile. The description adds meaningful behavioral context beyond those annotations: 'exactly as first computed' signals that the result is an immutable stored artifact, not recomputed or altered on retrieval.

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 that names the action, resource, and key content with no filler. Every phrase earns its place, and the most important identifier ('by its id') appears early.

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 annotations covering safety, an output schema available, and a clear id-based retrieval action, the description is largely complete. The only notable gap is the undocumented 'detail' parameter semantics, but the enum values are reasonably self-explanatory and the output schema likely clarifies return structure.

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 must compensate. It clarifies that backtest_id refers to a previous backtest result, but it does not explain the 'detail' parameter or its enum values ('summary', 'standard', 'full'). The phrase about honesty panel, equity curve, and per-trade detail hints at content but does not map those to detail levels.

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 states a specific verb ('Retrieve'), a precise resource ('previous backtest result by its id'), and the payload contents ('honesty panel, equity curve and per-trade detail'). It clearly distinguishes this from siblings like run_backtest (which creates new results) and list_backtests (which lists rather than retrieves a single result).

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 phrase 'previous backtest result by its id' makes the primary use case clear: when the agent already has a backtest id and wants the stored result. It does not explicitly name alternatives or exclusion conditions, but the context of siblings and the 'previous' wording imply it is not for running new backtests.

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