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

Annotations already provide idempotentHint=true and readOnlyHint=false, but the description adds valuable context: 'Badge is soulbound for 1 year, then transferable' and 'Free to call.' It also discloses the opt-in nature and the lasting benefit (20% off forever). No contradiction with annotations exists.

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 short sentences, each adding unique information: opt-in nature, eligibility and benefit, badge transferability and cost. It is front-loaded with the core action and avoids filler. Every sentence earns its place.

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?

Given a one-parameter schema with 100% coverage, an output schema, and annotations covering safety, the description is nearly complete. It communicates eligibility, benefit, and ownership constraints. It does not explicitly state prerequisites like holding a registered wallet, but that is not required for a simple claim action and is implied by the wallet parameter.

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% with the wallet parameter described as 'Your wallet address,' so the schema already carries the parameter meaning. The description does not add further detail about the wallet format or source. Baseline 3 is appropriate since the schema does the heavy lifting.

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 action with verb and resource: 'Claim the Plaza Services Soul Badge after 3 purchases.' It clearly distinguishes this from siblings like plaza.check_badge (check vs claim) and plaza.register (registration vs badge claim). The purpose is unambiguous and directly tied to the tool name.

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 specifies eligibility with 'after 3 purchases' and marks the action as 'OPT-IN', giving clear context for when to call. It does not explicitly name alternatives or exclusion conditions, but the condition alone is sufficient for an agent to route correctly. Sibling tools like plaza.check_badge are implicitly alternatives for verification.

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