check_tlsa_dane

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

Declares 'Read-only', 'No auth, no destructive actions.' Discloses lookup process and return values (parsed TLSA tuples, live cert digest, match verdict). Lacks details on potential errors or caching effects, but covers key behavioral aspects.

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?

Four sentences efficiently cover purpose, default behavior, parameter usage, and return values. Front-loaded with primary action and ends with usage guidance. No redundant 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?

Describes return values despite no output schema. Covers main functionality and usage scenarios. Slight gap in error handling or interpretation of verdict, but overall sufficient for a simple tool.

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?

Adds meaning beyond schema by explaining defaults ('Defaults to port 25 / tcp') and providing examples ('HTTPS (443), SMTP submission (587)'). Schema has 100% coverage, and description enriches parameter understanding.

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?

Description clearly states 'Read-only TLSA/DANE record check' with a specific verb (check) and resource (TLSA/DANE record). It distinguishes itself from sibling tools like check_smtp_tls, check_dmarc, etc., by focusing on DANE record verification.

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?

Explicitly says 'Use before publishing DANE records or when troubleshooting mail-handover failures with DANE-enforcing senders.' Provides context on defaults (port 25/tcp) and ability to check other ports. However, does not explicitly contrast with sibling tools.

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