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

The annotations already declare read-only, idempotent, non-destructive, and closed-world behavior. The description adds some output cardinality and default medium context, but much of that also appears in the schema, and it does not explain return structure, how existing UTM parameters are handled, or error behavior.

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 description is a single front-loaded sentence with no filler. The key action, default medium, and output modes are all presented efficiently.

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 an 8-parameter builder with no output schema, the description plus schema is mostly sufficient: url, tidy, platforms, and defaults are covered by the schema, while the description covers purpose and output cardinality. It still leaves return structure and edge-case behavior implicit, but the annotations reduce the need for further safety disclosure.

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 75%, so the baseline is around 3. The description usefully maps parameter names to UTM tags and indicates that content and term are optional, but it omits tidy and mostly repeats schema-supplied defaults for medium, source, and platforms.

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 states a specific verb and resource: adding utm_source, utm_medium, utm_campaign, and optional utm_content/utm_term to a link. It also clarifies the two output modes: one link per platform or one for a named source.

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?

Usage is implied for creating campaign tracking links, but there is no explicit when-to-use or when-not-to-use guidance. The sibling tools are unrelated, so lack of alternative routing is less harmful, but the description still gives no guidance on existing tagged links or exclusions.

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