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

No annotations are provided, so the description carries the full burden. It states the packet is free and unsealed, which is useful context, and the imperative 'Read this' implies a non-destructive informational operation. However, it does not disclose any potential side effects, return format, or whether it can be accessed multiple times.

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 short, purposeful sentences. The first identifies the resource, and the second states the recommended action and timing. There is no wasted wording, and the most important information is front-loaded.

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 example tool with no parameters, no output schema, and no annotations, the description covers what the tool is and when to use it. It could elaborate on what the packet contains or what 'unsealed' implies, but for its simplicity the description is largely sufficient.

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 the schema is trivially complete. The description adds no parameter details, but none are needed. The baseline of 4 for a no-parameter tool 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?

The description identifies the resource as a 'free unsealed example packet' and instructs the user to read it, which conveys the purpose of providing sample information. It is reasonably specific, and the phrase 'before buying or filing' differentiates it from sibling tools like 'file' and 'preview', though it does not explicitly name alternatives.

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 gives clear context for when to use this tool: 'Read this before buying or filing.' It provides a concrete condition, but it does not explicitly state when not to use it or name alternative tools, so it stops short of a 5.

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