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

Annotations already indicate read-only, open-world, and idempotent behavior. The description adds crucial cost information ($1 per call) and a passivity guarantee ('safe against any host'), which are beyond annotation coverage. It doesn't address error handling or output format, but the critical behaviors are disclosed.

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 concise sentences front-load the primary purpose, followed by safety and cost. No wasted words, each sentence adds distinct information.

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 gives high-level purpose, safety, and cost, but lacks information about return format or how to interpret results, especially with no output schema. It also doesn't mention chaining via previous_scan_id. This leaves some ambiguity for the agent, but the core purpose is clear, so a mid-range score.

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 description does not explain the hostname, port, or previous_scan_id parameters. While 'domain' implies hostname, the schema coverage is only 33% (previous_scan_id already described) and the description fails to compensate for the undocumented port parameter or clarify default behavior. A score of 2 reflects minimal semantic addition.

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 audits a domain's TLS configuration, listing specific aspects (certificates, protocols, ciphers, weaknesses). This distinguishes it from sibling audit tools like dns_security_check or email_security_audit by its focus on TLS.

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?

Provides clear context that this is a passive, safe read operation and costs $1 per call, guiding when to use it. However, it doesn't explicitly discuss alternatives or when not to use it, so not a 5.

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