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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds the return contract ('encoded payload, an SVG file and a PNG preview image'), which is valuable since there is no output schema. It does not cover sizing or failure behavior, so it falls just short of 5.

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?

Front-loads the core purpose and return values before the dense 'values by type' block. The compact mapping notation is information-dense and every token earns its place, though the run-on field list is slightly hard to parse.

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?

Covers purpose, output artifacts, and the complex nested parameter structure for a 7-param tool with no output schema. Only the visual customization parameters lack explanation, which is a minor gap given their defaults and enums.

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?

With 0% schema description coverage and a generic nested 'values' object, the per-type field mapping (url{url}; wifi{ssid,password,security...}; upi{vpa,name,amount,note}) is essential and well documented, including the WPA|WEP|nopass enum. The styling params (dark, light, margin, moduleStyle, errorCorrection) are left unexplained but are self-evident from defaults/enums.

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?

States a specific verb+resource ('Generate a scannable QR code') and enumerates every supported payload type (url, wifi, vcard, upi, etc.). No sibling tool produces QR codes, so the agent can immediately distinguish it from the conversion/formatting utilities.

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 enumerated type list effectively tells the agent which scenarios are supported and maps each to its required fields, giving clear usage context. It stops short of explicit when-not or alternative-tool routing, but no sibling overlaps this capability.

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