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

Without annotations, the description carries full burden. It specifies that the tool provides instructions for offline verification, which is a behavioral trait. However, it does not disclose what happens when the optional token is provided or the format of the explanation, leaving some ambiguity.

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 a single sentence with no filler, front-loading the action ('Explain') and specifying the exact resource and conditions. Every word 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?

For a simple informational tool with one optional parameter and no output schema, the description plus schema cover the essentials. However, the description doesn't explicitly state what the user should expect as a result (e.g., a step-by-step guide), which leaves a minor gap.

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?

The input schema fully documents the single parameter (token) with a description stating it is optional and verification is done offline. The tool description itself adds no parameter-specific information beyond the schema, so the 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 tool's function: 'Explain how to independently verify a MyDataPass delivery certificate (offline).' It uses a specific verb ('Explain') and resource ('delivery certificate'), and the offline/independent qualifiers differentiate it from any online verification tools. It stands apart from siblings which focus on general info, compliance, offboarding, and pricing.

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 the tool is for users seeking offline verification instructions, but it does not explicitly state when to use this tool over alternatives or when not to use it. No exclusions or alternative tool mentions are provided, so the guidance is implied rather than explicit.

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