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

Adds real behavioral context beyond the annotations: it consumes a pass use (consistent with readOnlyHint=false and idempotentHint=false), emits a Receipt, and specifies the failure contract (fulfillment_failed on source failure with no use consumed). That failure/refund semantics is valuable and not derivable from structured fields.

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?

Three compact sentences with no filler, front-loading the core action (consume a use, return reading) before the Receipt and failure notes. Appropriate length for the tool.

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 non-idempotent, mutating tool with 33% schema coverage and no output schema, the description covers behavior and failure mode well but leaves parameters and the returned reading structure unexplained. Adequate but with clear gaps.

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 only 33% (only 'symbol' is documented). The description never explains passId or sku, so it fails to compensate for the two undocumented required parameters beyond a vague allusion to the AccessPass.

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 names a specific verb+resource: it consumes one AccessPass use and returns a market reading ('lectura de los dioses'). It clearly differs from pure validation or tribute tools, though it does not explicitly name a sibling alternative.

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?

Usage is implied rather than stated: it signals this is the paid-with-pass path ('sin nuevo pago'), hinting at a contrast with payment tools, but it names no alternatives and gives no explicit when-to-use or when-not-to-use conditions.

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