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

Annotations already provide readOnlyHint, idempotentHint, and destructiveHint=false, covering safety. The description adds output composition (score, found records, fix records) but does not disclose behavioral details such as caching/rate limits, which are only in the refresh parameter schema.

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?

A single efficient sentence that front-loads the core purpose (score for a domain) and packs output details into one trailing clause. There is no filler or repetition of schema content.

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?

For a simple 2-parameter tool with rich annotations, the description is mostly complete: it names the return payload (score, DNS records found, exact records to publish) and the schema handles parameter details. It does not mention the sibling verification workflow or caching expectations, so a bit of context is left out.

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 coverage is 100%, so both domain and refresh are already documented, including domain format and reserved-name refusal as well as refresh's caching/rate-limit behavior. The description only adds 'DNS records found' and fix records, which relate to output rather than parameter meaning.

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 states the tool produces an email security score for a domain plus the DNS records found and exact remediation records, with the title naming MX/SPF/DKIM/DMARC. This is a specific resource+outcome that is easily told apart from check_discoverability, fetch_as_crawler, and verify_fix.

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 tool's email-security/DNS focus implies using it when a domain's email authentication or fix records are wanted. However, it does not explicitly mention when to prefer it over siblings like check_discoverability or verify_fix, so routing relies on inference from the name/title.

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