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

Annotations only declare readOnlyHint=false, so the description carries the burden and does so richly: what the yard keeps (hull materials + cargo), that payout is a fraction of local market value drawn from the manager's credits, that a broke manager cannot buy, that aboard modules go to your storage, and the wreck_not_here failure mode. This is exactly the behavioral context annotations cannot supply.

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 core action, then dense parenthetical detail; nearly every clause earns its place. It reads as a single long parenthetical wall, which slightly hurts scannability, but there is little padding.

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 a simple one-parameter mutation with no output schema, the description covers preconditions, payment mechanics, side effects, the alternative tool, and the specific error plus its fix. An agent has everything needed to invoke it 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?

There is one parameter (session_id) at 100% schema description coverage, so the schema already documents it fully. The description adds state requirements (tow claim, wreck at your POI), but nothing about the parameter itself, so 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 ('Sell a towed wreck') plus the counterparty (NPC salvage yard) and the currency received. It is clearly distinguishable from siblings like scrap_wreck, tow_wreck, release_tow, and loot_wreck without opening any 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?

Explicit preconditions ('Must be docked at an NPC station with a salvage yard'), explicit exclusions ('Player-owned yards don't buy wrecks'), and a named alternative with its trade-off ('scrap_wreck recovers far more, as materials'). It also routes the agent to the stale-tow remedy via release_tow.

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