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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds that the payload is daily AND cumulative P&L, which partially compensates for the missing output schema, but it says nothing about granularity guarantees, timezone handling, pagination, or empty ranges.

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 tight sentence with zero filler, front-loading what is returned before the use case. Nothing to trim.

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 3-parameter query with full schema coverage and no output schema, the description carries the return-value basics (daily + cumulative net P&L) and the intended question type. The remaining gap is time-series behavior (granularity, empty windows), but overall it is close to complete.

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%, covering 'to' (defaults to now), 'from' (defaults to all history) and accountId (from list_accounts, comma-separated, omit for all), so the baseline is 3. The description adds no parameter-level meaning beyond what the schema already states.

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 the specific resource (equity curve) and its content (daily and cumulative net P&L) over a period, which is more than a restatement of the name. It implicitly differentiates itself from siblings like get_monthly_performance and get_performance_summary via the 'daily and cumulative' framing, though it never names them.

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?

'For trend and drawdown questions' gives an implied usage context that helps an agent pick this over the monthly/summary siblings. However, it offers no explicit when-to-use / when-not-to-use statement and no named alternative, so the routing decision is left to inference.

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