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

No annotations are provided, so the description carries the full behavioral burden, and it discloses nothing: not whether output is returned as a string, whether input is mutated, what masking rules apply, or what permissions are needed.

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 sentence is short, but it repeats the tool name verbatim and contributes zero information, so its brevity reflects under-specification rather than efficient communication.

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?

A two-parameter tool with no annotations and no output schema requires a substantive description to be usable; this one provides none, leaving an agent unable to determine what masking produces or how 'text' differs from 'input'.

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 description coverage is 100%, so the baseline is 3. However, the schema's own labels ('Text to process' / 'Input to process') are generic, and the description adds no meaning to distinguish the oddly redundant 'text' and 'input' parameters.

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 'Mask Card: Mask card.' merely restates the tool name with no verb+resource specificity beyond what the name already conveys. It does not explain what 'masking' means (redaction? formatting? partial concealment?) nor distinguish it from siblings like x402-mask-email, x402-mask-phone, or x402-mask.

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?

No guidance whatsoever on when to use this tool versus the several other masking tools in the sibling list. There is no context, prerequisite, or alternative mentioned.

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