Realized returns

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

Annotations already declare readOnlyHint, idempotentHint and non-destructive, so safety is covered. The description adds meaningful behavioral context by spelling out how 'realized returns' is computed (account value minus net deposits, unrealized gains included), but says nothing about auth requirements, rate limits, or the response format beyond that definition.

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 sentence that front-loads the primary content (the cumulative return figure) and then the time series. The parenthetical definition earns its place, though the sentence is dense with parentheticals and could be tightened slightly.

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?

No output schema exists, so the description carries the burden of describing return content, and it does so adequately (cumulative return plus a series of account value, net deposits and returns). Combined with annotations that cover the read-only/idempotent safety profile, an agent has enough to call it correctly, though return shape and units are not detailed.

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 only 50%: the market enum is documented in the schema while the interval enum is not. The description restates the interval choices ('1M, 6M, 1Y or 2Y') but adds no format or default detail, and it does not explain the market values, so it only marginally compensates for the coverage gap. Baseline 3 for a mostly self-explanatory enum schema.

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 states a specific resource (cumulative realized returns plus a time series) and even defines the metric's formula (account value minus net deposits, unrealized gains included). It is clear what the tool produces, but it never names or contrasts with siblings like get_portfolio_performance or get_account_summary, so sibling differentiation is left to inference.

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 when-to-use guidance, no prerequisites, and no named alternative. An agent must guess whether to call this or get_portfolio_performance/get_account_activity based on the metric name alone.

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