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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered, but the description adds two non-obvious traits the schema cannot express: the cost is 'Free', and there is a fallback resolution path when the portfolio has never run. These genuinely extend what annotations provide.

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 leading with the verb and resource, with the fallback tucked into a parenthetical. Dense but no filler sentences, and the main action comes first.

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 and no annotation-derived return info, the description meets its burden by enumerating what comes back (equity numbers, trades, per-strategy parts) and covering the empty-history case. Read-only single-param tool, so little else is needed.

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% for the single required 'id' parameter, so the description must carry the meaning. 'Show a portfolio' weakly implies the id is a portfolio identifier, but it never states format or how it differs from a strategy id in this sibling-heavy family. Marginal compensation for the coverage gap.

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 (Show) and resource (portfolio) and clarifies that it returns the portfolio's latest run — combined equity, trades, and per-strategy breakdown — or the combined saved strategy results if it has never run. This is richer than a bare name restatement and hints at a distinct role versus siblings like get_run or get_strategy, though it does not name those alternatives.

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?

There is no explicit when-to-use guidance and no routing against the many portfolio siblings (get_run, get_equity_curve, list_portfolios, etc.). The fallback condition (never run → combined saved results) is a behavioral detail, not usage guidance, so an agent still has to infer when this tool is the right pick.

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