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

The readOnlyHint annotation already signals a safe read operation, and the description adds the year-to-date scope and the tax-loss opportunity output. It does not disclose calculation assumptions, response shape, or behavior for an invalid year, but for a read-only getter with annotations this is adequate.

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 sentence conveys both main outputs with no filler or redundant restatement of the tool name. It is front-loaded around the core purpose and the tax-loss opportunity add-on.

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?

For a simple one-parameter read-only tool, the description plus schema covers what the tool returns and the optional year input. A short note on what the returned tax-loss opportunities look like would have made it fully complete, but nothing is missing that would prevent a correct call.

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?

The input schema fully documents the single optional year parameter with its default behavior, so the schema carries the burden. The description does not discuss the parameter, but it does not need to at this coverage level.

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 names a specific resource: realized P&L since the beginning of the year, plus tax-loss harvesting opportunities. This is more than a restatement of the tool name, though it does not distinguish itself from sibling get_* tools such as get_transaction_history, so it stops short of a 5.

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?

The intended use is implied by the content: call this when the user needs year-to-date realized P&L or tax-loss harvesting ideas. However, there is no explicit when-to-use guidance, no exclusions, and no pointer to an alternative sibling.

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