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

Annotations already establish it is a non-destructive write (readOnlyHint=false, destructiveHint=false, openWorldHint=false). The description adds real context beyond that: cost behavior, a Pro tier requirement, and a preview of the returned analytics (equity, drawdown, Sharpe, contribution, correlation). It does not disclose persistence/auth details beyond the tier gate.

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 leads with the action, then the output, then cost/tier. Dense and informative with em-dash framing, and no filler. Slightly run-on but every clause carries value.

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 usefully previews return contents and adds cost/tier context. It is nearly complete for a create tool; minor gaps are the lack of linkage to downstream tools (e.g., run_portfolio) and behavior on name collisions.

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?

Top-level schema description coverage is 0%, so the description carries weight. It clarifies the 'weight' concept via 'each with a share of the capital' (the nested items do document id and weight with a default of 1). But the required 'name' parameter is never addressed, so the compensation is only partial.

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 specific verb and resource: 'Put several of your saved strategies together as a portfolio.' This is clearly the creation operation, distinguishable from get_portfolio (fetch), run_portfolio (execute), and update_portfolio (modify). The scope of the tool is unambiguous.

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?

Provides a cost guideline ('Combining saved backtests costs nothing') and a tier gate ('Pro'), which are useful usage signals. However, it names no alternative tools and gives no explicit when-to-use/when-not-to-use guidance relative to update_portfolio or run_portfolio, leaving the agent to infer.

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