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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds useful operational context: free pricing, direct call without x402, hosted reads never receiving keypair bytes, and local finalization for signed value-moving results. No contradiction with annotations; it lacks specifics like pagination, but the output schema covers returns.

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 purpose is front-loaded in a clear first sentence, followed by useful symbol examples. The second generic execution paragraph adds operational context but partially duplicates the input-schema description, introducing some redundancy without major bloat.

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 one-parameter read-only tool with annotations and an output schema, the description is complete: it defines what data is returned, how symbols are formatted, whether it costs anything, how to route it, and how it interacts with signing boundaries. Nothing essential for a correct call is missing.

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?

The schema already documents the single required symbol parameter with 100% coverage. The description adds meaningful value by explaining Backpack symbol conventions across market types and giving concrete examples like SOL_USDC_PERP, MU.US_USDC, and AAPL.US_USDC_RFQ, which helps the agent construct valid inputs.

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 verb and resource: 'Get Backpack funding-rate history for a perp symbol'. Concrete examples and marketType distinctions (spot, perp, stock, stock RFQ) make the tool's scope clear and distinguishable from sibling market/ticker tools.

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 gives clear execution context (read workflow, free, call directly, no signing) but does not explicitly name alternative tools or conditions for when not to use this tool. Usage is implied by the purpose rather than explicitly contrasted with similar Backpack or funding-history siblings.

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