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

Annotations already declare the mutation profile (readOnly=false, destructive=true, idempotent=true), so the description's real contribution is the cost model: exactly one token is spent and repeat calls are free. It does not say what happens when the wallet is empty (error vs. no-op) or that the spend is irreversible.

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?

Two tight sentences with the action/outcome front-loaded and the idempotency caveat immediately after; nothing is wasted.

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?

With no output schema, the description adequately signals the payoff (owner contact) and the cost, which is what an agent needs to decide. It is slightly short on failure modes — insufficient tokens, invalid or already-owned listing — but otherwise complete for a single-parameter tool.

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?

Only one parameter with 100% schema coverage, so the schema already explains parking_id as a public listing ID. The description reinforces that this is the 'listing' being unlocked but adds no format or lookup guidance beyond the schema.

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 ('consume one token') and a specific resource/outcome ('unlock a parking owner's contact'), which is clearly distinct from read-oriented siblings like get_owner_contact_access or get_my_token_wallet. An agent can pick this out without opening the 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?

The second sentence implies when the call is pointless (already unlocked) but never explicitly routes the agent to get_owner_contact_access for non-consuming reads or get_my_token_wallet to check balance. Usage is inferable rather than stated.

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