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

With no annotations provided, the description must carry the full burden of behavioral disclosure. It does so by enumerating the specific checks (credential signature, spend limits, trust score) and stating that it returns a verification receipt with approval status. It doesn't mention side effects or failure modes, but for a verification tool this is acceptable. The description adds useful detail beyond the tool name.

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 well-structured: a one-line summary, a bullet list of checks, then the Args block. It is concise without unnecessary fluff. The only minor inefficiency is the Args block repeating the parameter names already in the schema, but it adds needed context, so it's justified.

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 the core purpose, the checks, and all parameters. It mentions the return type (verification receipt with approval status) without elaborating since an output schema exists. It doesn't address error handling or prerequisites, but for a verification tool with a defined schema, this is sufficient. An agent has enough to call it correctly.

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 description coverage is 0%, so the description must compensate. The Args section provides meaningful explanations for all five parameters, including examples (e.g., '189.99' for amount, 'USDC' for currency). This goes beyond the schema's bare type/title and helps an agent construct correct 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?

The description states a clear, specific action: 'Verify a shopping transaction against a BuyerAgentCredential.' It names the resource (BuyerAgentCredential) and the context (shopping transaction), and lists the checks performed (signature, spend limits, trust score). This distinguishes it from other verify siblings like mt_skill_verify or mt_travel_verify, which target different domains.

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 implies when to use it: whenever a shopping transaction needs verification against a credential. However, it does not explicitly state exclusions or point to alternatives among the many sibling tools. For example, it doesn't say 'use mt_shopping_info for non-verification queries' or 'use moltrust_verify for general trust verification.' The guidance is adequate but not explicit.

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