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

The description discloses several behaviors beyond annotations: the share permalink continues to work, old slug address and campaign links break, slug normalization rules, uniqueness constraint, and the Pro workspace requirement. This is rich behavioral context that goes beyond the provided annotations.

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 concise (three sentences) and front-loaded with the main action. Each sentence provides unique information without filler, making it efficient for an agent to parse.

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?

The description covers the purpose, effects, constraints, and prerequisites. With no output schema, return values are not expected. The description is complete enough for an agent to invoke the tool correctly without additional context.

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 schema already describes each parameter (100% coverage), but the description adds meaning to the slug parameter by explaining normalization and uniqueness, and to workspace_id by mentioning the Pro requirement. This adds value beyond 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 clearly states the action ('Change a site's slug') and defines the slug's role in the URL, distinguishing it from sibling tools like rename_site and set_folder_slug. It is specific about what the tool does and what the slug is.

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 provides context on when to use it (changing a slug) and explains the effects (old URLs stop, permalink continues). It also mentions a prerequisite (Pro workspace). It does not explicitly name alternatives, but the context is sufficient for an agent to understand when to apply this tool.

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