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

The description significantly extends beyond the annotations (which only indicate non-read-only, non-idempotent, non-destructive). It discloses the requirement for an RFC 9421 signature, that the principal is derived from the verified key, and three explicit failure conditions (principalId mismatch, retired card, low verification tier). This is rich behavioral context beyond the structured annotations.

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 three sentences, front-loaded with the primary function, and every sentence adds critical information (purpose, auth, failure modes). No redundant or filler content.

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 purpose, authentication, principal semantics, and failure conditions—strong for a mutation tool. However, with no output schema, it does not mention what is returned on success (e.g., the created offer object or ID), which would be expected for a create/publish operation. Small gap but not enough to lower to 3.

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%, so all parameters have descriptions. The tool description adds a high-level semantic by explaining the two-step POST flow and reinforces that principalId must match the signing key, but this is already stated in the schema. It does not add new syntax or format details beyond the schema, so a 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 action: 'Creates and publishes an offer to the Mixer4AI network on behalf of the calling agent.' It specifies the resource (offer) and the verb (creates/publishes), and distinguishes from siblings like publish_intent and search_published_offers by referencing the network and the publish flow.

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 through context (requires signature, failure conditions), but there is no explicit comparison with alternatives. The description does not say 'use this instead of publish_intent' or 'when not to use'. It provides necessary context for when the tool will work but lacks direct alternative guidance.

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