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

With no annotations provided, the description carries the full burden for behavioral disclosure. It mentions the basic lookup functionality but omits any side-effect information (though a lookup is likely read-only), default behavior, or handling of edge cases. The note about exact versions is in the schema but not in the description, so the description alone is under-informative.

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, direct sentence with no redundant words or filler. It clearly conveys the core purpose without unnecessary detail, earning top marks for conciseness and structure.

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 description is adequate for a simple lookup but leaves gaps: it doesn't specify the return format (no output schema), the exact semantics of 'and/or', or how the tool behaves with exact version constraints. Given the tool's moderate complexity (4 parameters) and the presence of siblings, a bit more context would be helpful.

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%, so the baseline is 3. The description itself does not add parameter-level detail beyond the schema. The schema already provides rich descriptions for name, limit, cvss_filter, and retain_passing, so the tool's description need not repeat them.

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 uses a specific verb ('look up') and resource ('a package by name and optionally version'), and clearly states the outcome: finding available versions and/or vulnerabilities. This distinguishes it from sibling tools like is_vulnerable and most_recent_not_vulnerable, which are more targeted.

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 no guidance on when to use this tool versus the sibling tools (is_vulnerable, most_recent_not_vulnerable). It does not mention any prerequisites, exclusions, or alternative tools, leaving the agent to infer the appropriate context.

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