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

Annotations already cover read-only, idempotent, non-destructive behavior, and the description adds value beyond them by disclosing the exact scope (the key owner) and that all linked accounts are returned. It doesn't contradict the annotations and contributes useful behavioral context.

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 place the main action ('Get the Connect profile, scores, and all linked accounts') first, then give the intended use case. There is no filler or information that belongs only in annotations or schema.

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 output schema available, the description still tells the agent what data will be returned ('profile, scores, and all linked accounts') and for whom. A more detailed shape of the response would be helpful, but the purpose and invocation scope are complete.

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 and has a schema coverage of 100%, so the baseline is 4 and there are no parameters for the description to explain. The description appropriately adds no redundant parameter details.

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 names a specific verb ('Get'), the resources ('Connect profile, scores, and all linked accounts'), and the scope ('for the API key owner'). This makes it easy to distinguish from siblings like connect_scores_by_account or connect_lookup, which are not scoped to the current key 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 gives a concrete use case ('Use to identify which user the key belongs to'), which builds on the clear scope. It does not explicitly name alternatives or say when not to use the tool, so it stops short of full when/when-not guidance.

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