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

Annotations already establish that this is read-only, idempotent, non-destructive, and closed-world. The description adds useful context that the check is customer- and listing-specific, but it does not describe permissions, possible returned states, or rate behavior.

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?

A single, front-loaded sentence with no wasted wording. It communicates the core purpose efficiently.

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 simple, read-only status check with one fully described parameter and rich annotations, the description is nearly complete. It could be stronger by clarifying the expected result state or relation to redemption, but no major invocation detail is missing.

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 single parking_id parameter is fully documented in the schema with a clear description. The tool description adds no parameter-level meaning beyond the schema, so the high coverage 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?

States a specific check operation and resource: whether this customer has already unlocked owner contact for a parking listing. It implicitly differs from redemption, but does not explicitly name the related redeem_token_for_owner_contact sibling.

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 implies this is an access-status check, likely useful before attempting redemption, but it gives no explicit when-to-use guidance, exclusions, or alternatives. The presence of redeem_token_for_owner_contact makes that missing routing guidance notable.

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