Keel

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 discloses key behavioral traits: 'Safety limits: max 100 ports, rate-limited to one scan per second.' This adds valuable context about constraints and operational behavior beyond basic functionality, though it could be more detailed (e.g., error handling, output format).

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 appropriately sized and front-loaded: the first sentence states the core purpose, and the second adds critical safety information. Every sentence earns its place with no wasted words, making it efficient and easy 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?

Given the tool's moderate complexity (network scanning), no annotations, no output schema, and 0% schema coverage, the description is partially complete. It covers purpose and safety limits but lacks details on output, error cases, or deeper usage context. It's adequate but has clear gaps for an agent to use it effectively.

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 schema description coverage is 0%, so the description must compensate. It mentions 'common TCP ports' which implies the 'ports' parameter, but doesn't explain the 'host' parameter or provide details like format or examples. Since there are 2 parameters and the description adds some meaning for one, it meets the baseline but doesn't fully compensate for 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 purpose: 'Scan common TCP ports on a host.' It specifies the action (scan), resource (TCP ports), and target (host). However, it doesn't explicitly differentiate from sibling tools like 'port_check' or 'subnet_scan', which likely have overlapping functionality, so it doesn't reach the highest score.

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 mentions safety limits but doesn't specify scenarios, prerequisites, or exclusions. For example, it doesn't clarify when to choose 'port_scan' over 'port_check' or 'subnet_scan' from the sibling list, leaving usage ambiguous.

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