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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds useful context beyond that: free call without x402, hosted routing guidance, keep-it-small guidance, and a signer boundary statement about keypair bytes.

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 core purpose is front-loaded and efficient, but the SAP MCP execution guidance repeats 'free', 'call directly', and hosted-reader boundaries that also appear in the input schema. Those sentences are generic and somewhat redundant, though not distractingly long.

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 simple read-only tool with one optional parameter and a detailed output schema, the description covers what is returned, how to filter, symbol conventions, and execution/pricing behavior. No critical information 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?

Schema coverage is 100% and the sole parameter has an enum and description, so the baseline is 3. The description adds value with concrete examples like SOL_USDC_PERP and stock RFQ symbols, plus an explicit SPOT|PERP mapping.

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 states a specific verb and resource: 'List all Backpack Exchange markets with metadata (tickSize, stepSize, price, volume).' It is clearly distinct from the sibling sap_backpack_get_market by emphasizing 'all markets' and gives the optional SPOT/PERP filter.

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 clearly frames the tool as a read/discovery workflow and explains the optional marketType filter. It does not explicitly name alternative tools like sap_backpack_get_market or sap_backpack_get_tickers, but the context is clear enough for correct invocation.

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