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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavior: newest-first ordering, the fields present in each row, the SIMULATED caveat, and the POLYRANK_API_KEY auth requirement.

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 two short follow-ons; the scope and ordering come first, then the drill-down pointer, then the auth prerequisite. No redundant restatement of the title or annotations.

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 helpfully characterizes the row shape and ordering, and it flags the API key requirement. The only missing piece an agent needs to call it confidently is any hint about pagination or the default/max limit.

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, and it only partially does: '(all, or one strategy's)' conveys that strategy_id is an optional filter. The 'limit' parameter is never mentioned, nor is the maximum of 200 or the default page size, leaving the agent to guess at result volume.

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 concrete verb+resource ('Your recent backtests ... newest first') plus the exact payload fields returned ('status and headline'), and explicitly separates itself from polyrank_get_backtest and polyrank_list_strategies by scope. The '(SIMULATED)' tag further disambiguates the data domain.

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?

Gives a clear routing rule: use this to browse, then 'Read one in full with polyrank_get_backtest', and explains that omitting the strategy filter returns all. It stops short of stating when *not* to use it (e.g. vs. list_strategies or lab chats), so it falls just short of full coverage.

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