Create Glue Record

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

Annotations already declare idempotentHint=true, readOnlyHint=false, and destructiveHint=false. The description's only behavioral note, 'Idempotent', merely repeats the annotation and adds no new information such as auth requirements, error behavior, or conflict handling. With annotations covering the safety profile, a 3 is appropriate as the minimum viable, though the description adds little beyond them.

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 front-loaded with purpose and use case, and the four sentences are generally tight. The final sentence 'Idempotent.' is redundant because the annotation already declares idempotency, and the IPs sentence repeats the schema. Still, it is appropriately sized and easy to scan.

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 create operation with full schema coverage and annotations covering safety and idempotency, the description supplies the essential purpose and usage context. It does not explain return values or error behavior, and there is no output schema to compensate. However, the combination of description, schema, and annotations is sufficient for an agent to call the tool correctly, making it nearly complete.

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 all three parameters. The description's notes that 'subdomain is just the host part' and 'Provide IPs as an array of IPv4 and/or IPv6 addresses' mirror the schema descriptions exactly, adding no new syntax or format constraints. The 'domain' parameter is not mentioned at all in the description. Baseline 3 is correct when the schema does the heavy lifting.

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 a specific verb (Create) and resource (glue record for a host on a domain), and the term 'glue record' distinguishes it from the sibling create_dns_record. The example clarifies the exact scenario, allowing an agent to differentiate it from update_glue_record and delete_glue_record.

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?

It gives a clear use case: 'Used when running your own nameservers on the same domain they serve (e.g. ns1.example.com serving example.com).' This tells the agent when to choose this over a regular DNS record. However, it does not explicitly name an alternative tool or state when not to use it, so it falls short of a 5.

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