show_benchmark

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

Discloses key behaviors: uses daily snapshots when available for accurate time-series, falls back to cost-basis vs current value. No contradictions; vague on output format.

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 sentences, front-loaded core purpose, no unnecessary words. Efficient and clear.

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?

Explains behavior well but lacks description of return value format. Given no output schema, some output context would help. Still adequate.

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 already describes all parameters (100% coverage). Description adds only default values for benchmarks and from date, not significant extra semantics.

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?

Clearly states it compares portfolio return against benchmark indices, specifies default benchmarks (SPY and QQQ), and distinguishes from other show_* tools by focusing on benchmark comparison.

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?

Implies usage for comparison but does not explicitly state when to use or not use this tool versus alternatives (e.g., show_portfolio for overall portfolio view).

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