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

With no annotations provided, the description carries the full burden and delivers: 90-day token expiration, permanent QR deletion after ~180 days, one-time token display, and the requirement to claim an account before expiration. This is exceptional transparency for a zero-parameter tool.

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 longer than a single sentence but every sentence earns its place: purpose, warning, action item, and next step. The 'IMPORTANT LIFETIME WARNING' is clearly highlighted, and there is no filler.

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 zero-parameter tool with no output schema and no annotations, the description fully covers what the token does, its limits, expiration behavior, one-time visibility, and how to use it in MCP config. An agent has everything needed to invoke and consume the result.

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 schema has zero parameters and 100% coverage (empty object), so there is nothing to document; the baseline 4 applies. The description adds useful context about the token's 5-QR limit and Authorization header usage, which is beyond the schema.

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 opens with 'Get a free API token — no account or email required,' a specific verb+resource statement that clearly distinguishes this tool from the sibling QR code management tools. It establishes the token as a prerequisite for create_qr_code.

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 clearly states the next step: 'Add it to your MCP client config under Authorization: Bearer, then call create_qr_code.' It also explains when to use the account-claim alternative for persistent codes, though it does not explicitly contrast with sibling tools by name beyond create_qr_code.

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