mail_setup_yandex

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

Goes well beyond the destructiveHint/readOnlyHint annotations by disclosing exactly what is replaced (MX, SPF), what is preserved (other TXT, A, NS), and the destructive consequence of force with CAA/SRV. This is the kind of irreversibility detail annotations cannot express.

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?

Front-loads the one-line purpose, then structures the record details, DKIM note, and safety warning as distinct blocks. Slightly verbose in the DKIM section, but every block carries actionable 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?

With an output schema present, return values need no explanation, and the description fully covers behavior, side effects, precondition, and follow-up flow. Nothing needed to invoke this mutation correctly is missing.

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 0%, so the description must carry both params, and it does: fqdn is glossed as the domain name (site.ru) and force is tied to the CAA/SRV precondition. The glosses are correct but terse for a fully undocumented schema.

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?

States a specific verb and resource: sets MX and SPF for Yandex 360 in a single call. Explicitly enumerates the exact records (mx.yandex.net preference 10; v=spf1 redirect=_spf.yandex.net), which distinguishes it cleanly from the granular dns_set_mx / dns_set_txt siblings.

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?

Explains the multi-step DKIM workflow and points to dns_set_txt / domain_add_subdomain for the follow-up, and warns that CAA/SRV zones require force=True. It does not name mail_setup_mailru as the alternative for the Mail.ru case, leaving one routing decision to inference.

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