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

Annotations declare readOnlyHint=false, openWorldHint=true, non-idempotent, non-destructive. The description adds context the annotations do not: the sign-in requirement and the workflow expectation that the caller composes the message and includes the link. It does not disclose whether the produced link expires or is single-use.

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 short sentences, zero filler, with the core purpose front-loaded and the workflow constraint following. Every sentence earns its place.

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 5-parameter creation tool with no output schema and 80% schema coverage, the description supplies the auth prerequisite and the authoring workflow. The main omission is any indication of what the tool returns (the link itself) or link lifetime, though no output schema exists to cover that.

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 80%, so the schema already carries most parameter meaning (open, with, brief, token). The description adds no format or syntax detail beyond what the schema provides, so the baseline 3 applies.

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?

States a specific verb and resource ('Create an invite link for another person's agent'), which clearly separates it from read_invite, join_invite, and my_invites. It adds a concrete behavioral detail (you author the message and paste the link), but does not explicitly name or contrast a sibling.

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 parenthetical '(requires sign-in)' gives one prerequisite and the schema hints at a token alternative when not signed in, but there is no explicit when-to-use or when-not-to-use guidance relative to siblings like my_invites or share_workflow. Usage is implied rather than stated.

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