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

Beyond the annotations, the description discloses the lease model in detail: epoch increment on free/expired lines, renewal on reattach, owner-only switching of another cable's live lease, and renewal via writing. These are important side effects and conditions for a mutating, non-read-only tool, and they align with the annotation hints.

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 description is front-loaded with the core action and the returned identity package, then adds lease rules. It is dense and jargon-heavy, but for a tool with nontrivial lease semantics, most sentences carry useful information.

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?

Given the absence of an output schema, the description compensates by enumerating the identity package returned. It also covers lease acquisition, renewal, ownership switching, and epoch behavior, which are the key contextual details needed to invoke the 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?

The schema has 100% description coverage for both parameters, so the baseline is 3. The description adds the useful conceptual mapping 'cable = a model' but does not add further semantics for model or runs_on beyond what the schema already provides.

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 and resource: plug a session into its line and obtain the identity package including line, lease, epoch, persona, wiring, memory brief, and cursors. It is clear what the tool does, though it does not explicitly name sibling alternatives such as line_release or line_handover to sharpen selection.

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 clear context for when to attach: to take a free/expired line lease or to renew an existing attachment with the same cable. It also states the owner-only rule for switching live leases and notes that writing renews the lease, but it does not explicitly compare against sibling tools or list when not to use this tool.

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