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

Far beyond the readOnlyHint annotation: discloses never-cached behavior, delayed-quote marking at read time, auth requirements with the specific AUTH_REQUIRED failure mode for the stdio server, the honest-empty {has_portfolio:false, how_to_start} response instead of an error, and _meta.disclaimer / tool_notes caveats. This is exactly the behavioral context annotations cannot carry.

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?

Front-loaded with the core purpose and response shape, then packs auth, caching, and empty-state facts efficiently. Dense and clause-heavy, but nearly every sentence conveys a distinct operational fact.

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 enumerates the returned keys ({portfolio, positions, totals, position_theses, summary, has_portfolio}) plus the optional recent_trades shape and the empty-state payload, and covers auth, freshness, and cost. Nothing material for correct invocation is missing.

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 100%, and both parameters already document defaults and the 1..50 range, so the description's mention of include_history and history_limit largely restates structured data. Baseline 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?

States a specific verb/resource with unusual precision: 'YOUR paper (practice) portfolio on Oxford Ledge', and pins it to the same snapshot as the /practice/ web sandbox. It is clearly distinguished from live-portfolio siblings by the repeated 'paper/practice' framing, though it never names a sibling like get_portfolio_positions to contrast against.

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 implies context (caller's own portfolio only, requires auth) and offers the include_history toggle, but gives no explicit when-to-use/when-not guidance or routing to an alternative tool. Usage is inferable rather than stated.

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