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

Annotations already establish readOnlyHint=true and destructiveHint=false, so the description does not need to repeat those. It adds useful context that the id must come from search results, but does not disclose behavior on invalid ids or return details. Given the annotations cover the safety profile, this is adequate but not rich.

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 concise sentence with a clear verb and object, front-loading the action and resource. No filler or redundant information.

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?

For a simple fetch-by-id tool with annotations, the description covers purpose and id provenance. However, the existence of a sibling named get_backtest makes the lack of disambiguation a notable gap. The description would be more complete if it mentioned when to use get_backtest instead, or explained the difference.

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 meaningfully specifies that the 'id' is the identifier returned by search, clarifying the parameter's origin and expected type. While it does not describe format or validation, it provides essential semantic context beyond the bare schema.

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 action (fetch) and resource (document or backtest result), and adds provenance ('as returned by search') to clarify the id source. It is not a tautology and distinguishes from typical search tools, but it does not explicitly differentiate itself from the sibling get_backtest, which likely fetches backtest results specifically.

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 'as returned by search' implies a workflow but does not explicitly state when to use this tool versus alternatives like get_backtest or search. No exclusions or alternative recommendations are provided, leaving the choice between fetch and get_backtest ambiguous.

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