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

Annotations already declare readOnlyHint=false and openWorldHint=true; the description adds the asynchronous invitation flow, noting the invitee receives an email and becomes an editor only upon acceptance. It also clarifies that ownership is retained, which goes beyond the 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?

Two sentences with no filler. The core action, permission scope, ownership retention, and invitation flow are all stated in the minimum words needed to convey the information.

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 two-parameter tool with no output schema and no nested objects, the description covers the action, prerequisites, permissions, and post-invite behavior. It is sufficient for an agent to invoke the tool correctly.

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 0%, so the description must compensate. It implies that 'site' is a site the caller owns and that 'email' belongs to the invitee, but it never explicitly maps the email parameter to the invitee's address or describes expected formats, leaving some ambiguity.

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 ('Invite') with a clear resource ('a site you own') and defines the editor's permissions. It distinguishes this tool from siblings like remove_editor or transfer_site by spelling out what the invitee can do and what remains with the owner.

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 states a clear prerequisite ('a site you own') and explains the resulting access level, which tells an agent when this tool applies. It does not explicitly name or exclude sibling tools, but the context is strong enough to infer routing.

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