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

Annotations already mark the tool as read-only, idempotent, and non-destructive. The description adds meaningful behavioral detail beyond that: quota resets per UTC day, it is per IP, hosted chat apps share quota, and API-key callers bypass quota entirely. This is valuable context an agent needs to interpret the result correctly.

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 three sentences with no filler. The primary question is front-loaded, followed by two concise sentences that explain quota-sharing and the API-key exception. Every sentence adds needed context.

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 there are no parameters, strong annotations, and an output schema, the description provides all necessary operational context: the UTC-day window, IP-based quota, the hosted-app sharing caveat, and the API-key exemption. Nothing essential is missing for an agent to call and interpret this 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 tool has zero parameters, so there is no parameter semantic burden on the description. The schema already fully covers the empty parameter set, satisfying the baseline for no-parameter tools.

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 clearly states the tool's purpose: returning how many proofs can still be anchored today within the free public quota. It names the specific resource (quota) and the relevant qualifier (caller's IP, UTC day), which distinguishes it from sibling tools like anchor_proof and check_proof.

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 does not name an alternative tool, but it gives clear context on when the quota applies and how the caller is classified: hosted chat apps share one quota, while callers with an X-API-Key header have no quota. This effectively tells an agent how to interpret the result, though it stops short of explicit when-to-use versus alternatives.

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