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

Annotations are minimal (not read-only, not destructive), so the description carries the behavioral burden. It adds meaningful context: the binding persists across subsequent tool calls, affects attribution in leases/receipts/audits, and requires an owned worker. It doesn't spell out whether an existing binding is overwritten or how to reverse it, but the core stateful behavior is disclosed.

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?

Three sentences, each earning its place: purpose, behavioral impact, and usage boundary. The most important constraint ('call this only to reuse an existing worker') is clearly positioned at the end without burying the core definition.

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?

For a single-parameter, no-output-schema tool, the description is complete: it explains what happens, when to call it, when not to, and where to get the required worker_id. An agent has enough context to select and invoke this tool correctly.

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 coverage is 100% and the schema already describes worker_id as 'A worker you own, from whoami' with format/pattern constraints. The description adds no additional parameter-level meaning, so the baseline of 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?

The description states a specific action ('Point this MCP connection ... at a specific worker you own') and a clear resource (the connection/worker binding). It also distinguishes itself from the sibling creation flow by explaining that Tango auto-provisions on first use and this tool is only for reuse.

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 explicitly says when to use the tool: 'call this only to reuse an existing worker instead.' It also explains the default alternative (auto-provisioning) and the consequence of use (subsequent calls attributed to that worker), giving an agent clear decision criteria.

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