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

Annotations already cover the read-only/non-destructive profile, and the description adds substantial context: the exact return payload (512 px PNG plus SVG markup), the persistence semantics of static codes, a real-world scanner caveat about light-on-dark colors, and the three explicit error conditions.

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?

Four tight sentences, front-loaded with what the tool produces and followed by constraints and failure modes. Every sentence carries information an agent would otherwise have to discover by trial.

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?

With no output schema, the description covers return format (PNG resolution and SVG), the mutability/persistence story, and error behavior, which is everything needed to call this read-only utility correctly without surprises.

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%, so the baseline is 3, but the description adds enforcement detail the schema does not: the 800 UTF-8 byte ceiling on text and the six-digit-hex requirement on colors as an error condition. Only errorCorrection is left entirely to the schema, which documents it well.

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 and resource ('Make a static QR code') plus the input domain ('a link or any text'), which is unambiguous and clearly distinct from the unrelated sibling utilities like base64 or hash_text. An agent can decide instantly whether this is the right tool.

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 word 'static' plus 'never expires and needs no account' implicitly contrasts with hosted/dynamic QR services, giving useful context for when this tool applies. It lacks an explicit when-not-to-use statement, but the input constraints (800 bytes, text only) effectively bound the use case.

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