get_fund_performance

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

With no annotations, the description carries the full burden and does so well above average: it discloses that the benchmark comparator is not yet implemented, that it defaults to Direct/Growth with a warning when that plan is absent, and that it never emits scores/ratings/recommendations. Remaining gaps are operational (rate limits, response shape), not trust-relevant.

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?

Front-loads the purpose in the first sentence, then uses terse labeled lines for metrics/comparators and one caveat sentence. Compact and every line adds something, though the parenthetical about benchmark is slightly verbose.

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 an 8-parameter tool with no output schema and no annotations, the description covers behavior and two enum-like parameters reasonably but omits period format, the meaning of nav_series, and rolling_windows units. An agent can call it, but not with full confidence on the unaddressed parameters.

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 0% across 8 parameters, so the description must compensate. It documents valid values for metrics ('trailing','rolling','risk','drawdown','stress'), comparators ('benchmark','category'), and the plan default, but leaves period, nav_series, rolling_windows, and scheme_ids semantics unexplained.

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 a specific resource ('Complete return/risk evidence pack') and behavior ('list = comparison'), which is enough to distinguish it from get_fund_profile or get_fund_portfolio. It stops short of explicitly naming the sibling it is not, so it lands at 4 rather than 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 description implies usage through 'list = comparison' and the enumeration of metric/comparator options, and warns about the Direct/Growth default. But it never states when to reach for this tool vs get_fund_profile or get_fund_portfolio, so the routing guidance is only implied.

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