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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely new behavioral context: the link is workspace-scoped, never carries tokens or secrets, and is only a handoff into the Mark app rather than an in-API connection. That out-of-band workflow detail is exactly what annotations cannot convey.

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?

Front-loaded with the return value and its security constraint; the workflow sentence earns its place. The trailing 'Related:' list of four siblings is mildly redundant given several are already named inline, but it aids routing rather than bloating.

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 the description covers the one parameter, the security constraint, and the follow-up workflow. An agent has everything needed to call this correctly and interpret what happens next.

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 parameter description already covers 'connectionId from list_connections, or a channel such as linkedin.' The prose restates the same semantics without adding format, validation, or example detail beyond the schema, so the baseline 3 applies.

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 ('Returns the in-app URL to connect a provider') and immediately scopes what the provider argument can be. It distinguishes itself from siblings by referencing list_connections' ids and channel names, so the agent can route correctly without opening another 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 explicit when-to-use and what-comes-next guidance: the connection itself happens in the Mark app, then sync_connections should be called, and for social channels list_channels reveals connection state. It also names related tools, leaving nothing to inference.

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