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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds traits the annotations don't capture: it opens the client's sign-in window (a visible UI side effect) and returns the user's identity. It stops short of describing decline/failure handling, so not a full 5.

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 action is front-loaded in the first clause, followed by the precondition, the side effect, and the follow-up call. Every clause carries distinct information with no filler.

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 no parameters and no output schema, the description still tells the agent what triggers the call, what side effect to expect, and what the return conveys ("returns who they are"). Nothing needed to invoke it correctly is missing.

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 tool takes zero parameters, so parameter semantics is trivially satisfied and the baseline is 4. There is nothing for the description to disambiguate.

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 ("Sign the user in to Replo") and is immediately distinguishable from siblings like connect_custom_domain or get_integration_status, which are domain/status operations rather than authentication. An agent can tell this is the sign-in/auth tool without opening the schema.

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?

Gives an explicit precondition ("only after the user agrees to connect an account") and a concrete trigger ("usually after a tool returned status sign_in_required"). It also routes the agent forward with "Then call list_workspaces", so both when and what-next are covered.

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