Fund Performance Comparison

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered and the description correctly does not contradict it. The description adds the counter_id provenance and the optional period behavior, but says nothing about return shape, comparison universe, or how peers are chosen.

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?

Two compact sentences with no filler, leading with the tool's purpose and following with the input-sourcing hint. Efficient, though the second sentence is fragmentary rather than fully formed guidance.

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 a fully described schema, read-only/idempotent annotations, and no output schema, the short description is nearly sufficient for correct invocation. The only real gap is the absence of sibling differentiation and any comparison-universe detail, which is minor given the structured coverage.

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%, so the schema already documents counter_id (with example), period, and _jq. The description only corroborates the counter_id source and the period's optionality, adding no syntax or semantics beyond the schema — the baseline 3 for high-coverage schemas 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?

Names a specific verb (Compare) and resource (a fund's performance) with explicit scope (against benchmark/peers). However, it does not distinguish itself from the sibling fund_performance or fund_position_performance, so an agent cannot tell from the description alone which of these performance tools to pick.

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?

Provides a useful data-source hint (counter_id from fund_hot / fund_list) and notes the period selector is optional, which is implied usage guidance. It stops short of stating when to use this comparison tool versus the plain fund_performance sibling, leaving the key routing decision to inference.

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