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 covered. The description adds valuable behavioral context: it distinguishes measured from forecast, and notes that crises before a holding's existence are named as 'not tested.' This goes beyond annotations and helps the agent understand edge cases and output semantics.

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?

The description is compact and front-loaded: it states the main action, the crises covered, the output metrics, and the handling of missing history in just a few sentences. Every sentence adds information, with no redundancy or filler.

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?

The description covers the essential behavioral contract (what is replayed, what metrics are shown, how missing history is handled) and relies on the existing output schema for return structure. Combined with the fully described schema, an agent has all necessary information to call the tool correctly.

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% for both parameters ('base' and 'holdings'), so the schema already documents their meaning and defaults. The description reinforces the money-vs-weight distinction already in the schema, but does not add new parameter-level details. With full coverage, the baseline of 3 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?

The description clearly states the tool's purpose: it replays holdings through past crises and reports the fall, worst day, and recovery time. It names specific crises (2008, 2020, 2022) and clarifies that it is measured, not forecast. This is a specific verb+resource with no ambiguity, and it is distinct from sibling tools that focus on comparisons, structure, or validation.

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 when to use the tool (when you want historical crisis behavior for holdings) but does not explicitly compare it to alternatives or state when not to use it. It provides context on input formats (weights vs amounts) but lacks explicit routing among the listed sibling tools. The usage is clear enough from the title and description, but no exclusions or alternatives are mentioned.

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