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

The description adds a useful behavioral note: the defaults are 'never asked for', so the agent knows not to expect prompts for those values. But it leaves side effects like output-file handling, overwrite behavior, and download-link expiry to the schema, and the annotations are all false, so they provide no safety context.

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?

Two sentences with no filler. The first sentence states the purpose, and the second delivers the key defaulting behavior. Everything earned 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 14-parameter tool with no output schema and no positive annotations, the description covers the core use case and default policy but does not describe the return/output behavior, such as inline SVG vs PNG download link. The schema helps, but the description itself is not fully standalone.

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. The description adds cross-parameter meaning by grouping name, phone, email, and address as a shared default set and explains that passing nothing is the correct approach for one's own card, which is not fully captured per-parameter in 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 uses a specific verb ('make') and a specific resource ('QR code that adds a contact when scanned (vCard 3.0)'). The 'vCard 3.0' detail clearly differentiates this from sibling QR tools, though it does not explicitly name them.

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?

It explicitly tells the agent when to call the tool and gives a concrete usage rule: pass nothing for your own card because name, phone, email, and address default to the shared business profile. However, it does not mention when not to use it or name alternatives among the QR siblings.

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