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 needs no restating. The description adds value by disclosing the data payload (holdings, return horizons, risk metrics, SPY benchmark) and the public-only constraint. It doesn't mention what happens with an invalid or stale URL, which is the one remaining behavioral unknown.

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 with the trigger front-loaded and exclusions trailing, so the reader hits the decision rule first. The long metric list is informative but slightly overstuffed for a description whose output schema already enumerates the returns.

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 an output schema present, the description needn't detail return structure, and it correctly focuses on selection criteria and scope. Combined with full annotation coverage and a single required parameter, the definition is essentially complete; only failure-mode behavior for a bad URL is left unstated.

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?

There is a single parameter with 100% schema description coverage, and the schema already states it is the Redstone URL as returned by search_portfolios. The description's phrase 'usually a search_portfolios result' reinforces the provenance but adds no format or validation detail beyond the schema, so the baseline of 3 applies.

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 opens with a specific verb-and-resource ('get one public Redstone portfolio') and immediately enumerates what comes back: holdings with per-holding figures, multi-horizon returns, drawdown, volatility, Sharpe, beta, dividend yield, charted against SPY. It also scopes the tool to public portfolios, which separates it from private-portfolio behavior and from backtest_portfolio without requiring the schema to be read.

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?

It gives an explicit trigger ('when the user asks about one public Redstone portfolio, usually a search_portfolios result') and explicit exclusions with the alternative named: a portfolio the user describes goes to backtest_portfolio, and private portfolios are out of scope. The routing decision is fully determined from the description alone.

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