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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context: it is a bootstrap read meant to precede mutations, it lists what the response surfaces (you.can, you.send_policy, per-limit usage, what's on/off, what needs attention), and it explains that suggestions attribute each action to the agent or the person. It stops short of describing partial-failure or staleness behavior.

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 opening clause is well front-loaded, but the second sentence is a long nested enumeration of return fields that largely duplicates the output schema, and the parenthetical asides ("Instagram DM automation such as comment-to-DM and follow to unlock...") add bulk before the actionable content. Every sentence roughly earns its place, but the return-value inventory is wasted words.

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 already present, the description is more than complete for a zero-required-param read: it covers when to call, when to re-call, and how to interpret the suggestion ownership. The only redundancy is that it restates return fields the output schema already defines.

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 100% and the single `detail` enum is fully documented in-schema (concise vs. full, with the extra fields enumerated). The description adds nothing about the parameter, so the baseline of 3 applies — the schema does all the work here.

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 role — the entry-point read that returns the acting profile, connection capabilities, plan usage, social accounts and next-step suggestions — and explicitly separates itself from postkey_guide ("For how Postkey works ... use postkey_guide"). An agent can tell it apart from the ~50 siblings without opening a 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?

It gives explicit triggers (person asks about profile/setup/next steps; before creating, scheduling or publishing), a re-call policy ("One call is enough for a piece of work; call again after a refusal or when the person asks"), and routes explainer questions to the named alternative postkey_guide.

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