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

With no annotations, the description carries the burden of behavioral disclosure. It adds useful context: it includes state CSRs and mid-level registrations, and sets a default 90-day window. However, it does not explicitly state that it is read-only, nor does it mention return format, pagination, or any side effects. It implies a read operation via 'List' but leaves significant behavior unspecified.

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, front-loaded sentence with no redundant words. It states the verb, resource, scope, and a key default. Every word earns its place.

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 one-parameter tool with no output schema, the description covers the purpose and the default window adequately. However, it omits any detail about the response structure (e.g., what fields are returned), which is often needed for an agent to correctly consume the output. Given the absence of an output schema, this is a notable but not critical gap.

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?

Schema description coverage is 100% — the schema already describes the 'days' parameter as 'Look-ahead window in days (default 90)'. The description repeats this default without adding new meaning. Per the baseline rule for high schema coverage, a score 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?

States a specific verb ('List') and a precise resource ('controlled substance registrations expiring within the next N days'), and further clarifies scope by mentioning 'including state CSRs and mid-level registrations'. This clearly distinguishes it from sibling tools like search_registrations (general lookups) and export_registration_report (exports).

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 usage: if you need expiring registrations, use this tool. However, it does not explicitly state when not to use it or name alternatives (e.g., search_registrations for broader queries). Context is clear but exclusions are absent, so it falls at 'implied usage' level.

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