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 does add context by indicating the operation is 'read from the daily archive' (suggesting read-only) and that a key is required, but it does not describe return format, error behavior, or what counts as a change. This is moderate disclosure, not exceptionally rich.

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 that front-loads the core purpose and adds a necessary link for key requirements. There is no redundancy or unnecessary detail, making it highly efficient for an agent to parse.

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 only two parameters, but it has no output schema and no annotations. The description explains purpose and authentication but does not describe the return value or potential pitfalls. For an agent to correctly use the tool, the input semantics are reasonably clear from the schema and description, yet the missing output details leave a gap, so this is only adequate.

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 coverage is only 50% (only 'since' is described in the schema). The description partially compensates by mapping 'a set of packages' to the 'names' parameter and 'since a given date' to 'since', but it does not clarify the format of package names or behavior for edge cases like empty arrays. It adds some meaningful context but does not fully close the coverage gap.

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 function with a specific verb ('What changed') and resource ('a set of packages', 'since a given date'), and adds the data source ('daily archive'). It distinguishes from sibling tools by focusing on historical diff for multiple packages, but does not explicitly name alternatives, so it falls short of a 5.

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 the usage context (comparing package states over time) and mentions a prerequisite ('Requires a key'), but it does not provide guidance on when to use this tool versus alternatives like watch_changes or check_package, nor does it state exclusions. This matches 'implied usage' rather than explicit guidance.

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