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

readOnlyHint=true already covers the safety profile, lowering the bar. The description adds the specific computed metrics (daily curve, return, drawdown, volatility, benchmark comparison) which is useful substantive context. No contradiction with annotations, but no extra behavioral detail like response format or data granularity is disclosed.

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 with zero waste states the core output (capital curve) first, then lists metrics compactly. It is genuinely concise, though written in Polish rather than English.

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 read-only analytics tool with two optional, fully-documented parameters and readOnlyHint set, the description adequately conveys the deliverables. The main gap is the absence of an output schema and hence any statement about the return structure, which is minor given the tool's simplicity.

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% — period and benchmark are both fully documented with enums, defaults, and explanatory descriptions of what WIG/SPY/QQQ represent. The description's mention of 'WIG or S&P 500' partially duplicates the schema's benchmark enum. Baseline 3 applies since the schema does the heavy lifting.

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 specific outputs — daily capital curve, return rate, drawdown, volatility, and benchmark comparison — making the resource and purpose concrete. However, it is a noun phrase without an explicit verb, and it does not name any sibling tool to distinguish itself from the many get_portfolio_* 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?

No guidance is given on when to use this tool versus the numerous siblings (get_portfolio_value_history, get_portfolio_stats, get_total_portfolio_view). The description implies portfolio performance analysis but provides no exclusions or alternative-routing cues, leaving selection to inference.

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