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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=true, so the safety profile is largely covered. The description adds the useful outcome detail that the session reverts to guest mode, but it does not say whether stored credentials or tokens are revoked, whether the action is reversible, or what happens to in-flight authenticated operations.

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 filler, front-loading the action and then the resulting state. Every clause adds 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?

An output schema exists, so return values need not be explained, and annotations cover safety. However, for a mutation that changes authentication state, the description leaves open whether tokens are cleared and how `session_id` affects scope of the logout, which an agent needs to know before calling it in a multi-session 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?

Schema coverage is 100% for the single optional `session_id` parameter, so the schema already documents it and a baseline of 3 applies. The description never clarifies what `session_id` controls, and in particular whether omitting it logs out the current session or some default; that is a meaningful gap not compensated for elsewhere.

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 pairs a specific verb ("unbind") with a specific resource ("the current MCP session" / "the linked Gooo Short user account") and states the resulting state ("guest mode"). Its meaning is unambiguous and is naturally distinguished from the sibling `login` by antonym, though it does not name any sibling explicitly.

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 purpose strongly implies the use case (returning to guest mode, for example to switch accounts or after finishing account work), but there is no explicit when-to-use or when-not-to-use guidance, and no mention of prerequisites such as being currently logged in. An agent must infer its own trigger conditions.

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