check_srv

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: parallel probing, ~16 common prefixes, and flagging of insecure advertisements such as plaintext IMAP/POP3 without encrypted variants. No contradiction with annotations.

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 two sentences, front-loaded with the main action, then output, then usage guidance. Every sentence earns its place with no wasted words or redundancy.

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 strong annotations, full schema coverage, and presence of an output schema, the description is complete enough. It explains what the tool does, what it returns, and when to use it, without needing to repeat structured field details.

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 schema already documents domain, format, and force_refresh. The description adds general context about SRV probing but does not add parameter-specific meaning beyond what the schema provides, so baseline 3 is appropriate.

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 maps a domain's DNS-visible service footprint by probing ~16 common SRV record prefixes, which is a specific verb+resource+method. It distinguishes itself from sibling DNS tools like check_mx or check_spf by focusing on SRV records and insecure service advertisements.

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 explicitly says 'Use when asked to map DNS-visible services or flag insecure service advertisements,' giving clear context for when to invoke it. It does not explicitly mention when not to use it or name alternative tools, but the usage guidance is sufficient for selection.

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