run_deliverability_audit

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the agent knows this is a safe, non-mutating operation. The description adds that it returns prioritized findings and covers multiple areas, but it does not disclose other behavioral traits such as potential latency or whether it invokes external services. No contradiction with annotations, though the added context is modest.

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, well-structured sentence that packs a complete scope into a compact list of audit areas. Every word contributes meaning, with no repetition or filler.

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 tool is moderately complex with multiple audit dimensions, and the description lists them all, giving the agent a clear sense of what the operation covers. With no output schema, the description notes the return type ('prioritized findings'), which is helpful but somewhat generic; additional detail on the output format (e.g., list vs. score) would improve completeness. The zero-parameter interface and strong annotations reduce the burden, so a 4 is appropriate.

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 tool has zero parameters, so the input schema is trivially complete. The description appropriately doesn't mention parameters. Given that there are no parameters to explain, the baseline of 4 applies.

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: 'Run a full deliverability audit' and enumerates the specific areas covered (authentication SPF/DKIM/DMARC, domain reputation, list hygiene, content signals, blocklist status). The verb 'run' plus the resource 'full deliverability audit' is specific and distinguishes it from narrower sibling tools like 'get_deliverability_score' or 'check_dmarc'.

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 clear context: use this when a comprehensive, multi-area deliverability audit is needed. It implies a broader assessment than the focused sibling tools, but it does not explicitly name alternatives or state when not to use it, so it lacks full exclusion guidance.

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