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

Annotations only provide readOnlyHint=false, so the description carries the transparency burden. It discloses the prerequisite module, the side effect of reduced speed, and the single-tow limitation, which meaningfully describes behavior beyond the annotation.

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 a single parenthetical that packs several important pieces of information: prerequisites, side effects, follow-up actions, and constraints. It's slightly dense but all content is relevant and the core purpose is front-loaded.

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 two-parameter tool with no output schema and minimal annotations, the description covers prerequisites, travel implications, and the one-tow rule. It omits mention of how to detach (e.g., release_tow) or what happens if the player is already towing, but it's still substantially complete for the tool's simplicity.

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 input schema already fully describes both parameters, including wreck_id's reference to get_wrecks and session_id's login origin. The description adds no parameter-specific semantics beyond the schema, so the baseline of 3 is appropriate.

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 opens with the specific verb 'Attach' and resource 'tow line to a wreck for hauling', clearly identifying the tool's function. It distinguishes itself from sibling tools like sell_wreck, scrap_wreck, loot_wreck, and release_tow by focusing on the attachment action.

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 provides strong usage context: it requires a tow rig utility module, warns that speed is reduced while towing, tells the user to travel to a salvage yard to sell/scrap, and explains the one-tow-at-a-time constraint. It doesn't explicitly name alternative tools like release_tow, but the when-not constraints ('never both') give clear operational boundaries.

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