get_portfolio_performance

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly notes 'Requires API key,' covering authentication needs. The verb 'Get' implies a read-only, non-destructive operation, but the description does not explicitly confirm the absence of side effects or describe behavior for empty/unavailable data, so it is slightly incomplete.

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?

The description is a single, information-dense sentence that front-loads the action and resource, then efficiently lists the metrics, breakdowns, and authentication requirement. Every phrase adds value with no redundancy or filler.

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 tool with one optional parameter and no output schema, the description covers the core information: what it returns (three metrics), how it groups them (three breakdown dimensions), and the auth prerequisite. It does not specify the exact response shape, but the described data elements are sufficient for basic invocation.

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?

The sole parameter (days) is fully described in the schema with its enum values and default, yielding 100% schema coverage. The tool description adds no additional parameter semantics beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 clearly states the tool retrieves platform-wide portfolio performance statistics, enumerates the specific metrics (win rate, average return, median return), and describes the breakdown dimensions (AI score range, opportunity score range, weekly cohorts). It distinguishes itself from ticker-specific performance tools like get_ticker_performance by emphasizing 'platform-wide' scope.

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 description establishes unambiguous context: this is the tool for aggregate portfolio-level performance stats, implying use when cross-position or platform-wide metrics are needed. It does not explicitly name sibling alternatives or state when not to use it, so it stops short of a full 5.

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