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

The description adds the optional x-default behavior and the multilingual page context, but does not disclose the output format (e.g., whether it returns HTML link elements, a string, or an array). The readOnlyHint annotation already covers safety, so the description provides limited additional behavioral 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?

One sentence with no redundant words; the action and optional parameter are stated clearly. It is appropriately sized and front-loaded.

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?

There is no output schema and no parameter descriptions, and the description doesn't cover return format or input validation. For a tool with a non-trivial array input, this is insufficient for correct invocation.

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 description mentions 'optional x-default' but does not explain the structure of the required 'rows' parameter (array of objects with url and lang). With schema_description_coverage at 0%, this is a significant gap.

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 the specific verb 'generate' with the resource 'hreflang link tags' and clarifies the domain (international/multilingual pages). This clearly distinguishes it from sibling generators like canonical-tag-generator or meta-tag-generator.

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 suggests usage context (international/multilingual pages) but does not explicitly state when to choose this tool over alternatives or when not to use it. The use case is implied rather than articulated.

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