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

Annotations only declare that this is a non-destructive, non-open-world mutation, so the description carries most of the behavioral weight and does so well: the link expires in 10 minutes, is one-time, and requires an out-of-band Google Login step by the user. It does not clarify whether repeated calls invalidate prior links or whether an existing session binding is overwritten, which would matter for a session-mutating tool.

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?

A single front-loaded sentence leading with the action and its key constraint (10-minute, one-time) before the purpose. No filler, no restatement of the title, and every clause carries information an agent needs.

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?

With an output schema available, the description need not explain the returned link, and annotations cover the safety profile. It still leaves the caller guessing about the prerequisite flow (user must complete Google Login externally) and about re-invocation semantics, which are the main remaining gaps for an auth-initiation tool.

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?

Both parameters are fully documented in the schema (session_id and client_name with examples), so the 100% coverage baseline applies. The description adds no meaning beyond the schema, such as how client_name is used or whether session_id defaults to the current session, so the baseline 3 is correct.

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 (generate) and resource (10-minute one-time authorization link / Magic Link), plus the effect of that resource: binding the current MCP session to a Gooo Short user account via Google Login. This clearly separates it from siblings such as logout, get_user_profile, and check_code_availability, which handle session teardown, profile reads, and availability checks rather than authentication initiation.

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 implies the usage context (you are not yet bound to an account and need to authenticate), but it never states that explicitly, nor does it say when not to call it (for example, when already authenticated), whether it must precede other authenticated tools, or what to do with the returned link. Usage is inferable rather than directed.

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