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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only states it returns 'Status/Tracking' for a brief by ID, implying a read-only operation, but does not disclose any details about the response format, possible statuses, error conditions, or whether tracking history is included. The minimal wording leaves significant behavioral ambiguity.

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, concise sentence with no redundant wording. It is front-loaded with the core concept 'Status/Tracking' and immediately specifies the resource and required parameter. Every part of the brief description earns its place, making it highly efficient.

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?

The tool is simple with one parameter and no output schema, and the description provides the essential information: it returns status/tracking for a brief by ID. However, without an output schema, the description does not explain what return values to expect, leaving a gap in completeness. An agent would likely know the tool's basic function but might not know the exact statuses or tracking data returned.

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 input schema has 100% coverage for the single required parameter 'id' with description 'Brief-id.' The description's phrase 'per id' adds no additional meaning beyond what the schema already provides. Since schema coverage is high, the baseline of 3 applies, and the description doesn't compensate with extra semantic detail.

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 identifies the tool's purpose as retrieving status/tracking information for a brief (letter) by ID. While it lacks an explicit verb like 'get' or 'retrieve', the noun phrase 'Status/Tracking' conveys the action. It distinguishes itself from sibling tools like envelope_status and fax_status by specifying the target entity (brief).

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 provides no guidance on when to use this tool versus alternatives. It does not mention sibling tools (e.g., envelope_status, fax_status) or specify contexts where this tool is preferred. The only implied usage is that it is for briefs, but no explicit when-to-use or when-not-to-use guidance is given.

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