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

Beyond the destructiveHint annotation, the description discloses that it is a WRITE operation, that changes take effect on live DNS, and that fields not explicitly passed may be lost unless carried over from a prior read. This goes well past the annotation by explaining the practical destructive consequence and required workflow.

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 the critical WRITE warning, then flows into purpose, side effects, prerequisite read, field-preservation guidance, and the underlying endpoint. Every sentence is useful and no filler is present.

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 15-parameter mutation tool with only a destructiveHint annotation and no output schema, the description supplies the essential operational context: live effect, prerequisite read, and preservation of fields. No output schema exists, so omission of return-value details 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?

Schema description coverage is 100%, so the baseline is 3. The description adds meaningful workflow semantics by explaining that required fields type, name, and value must be supplied along with any other fields the agent wants to preserve, which clarifies how the update interacts with the existing record.

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 and resource ('Update an existing DNS record') and begins with 'WRITE', immediately distinguishing it from read operations like bunny_list_dns_records and from creation via bunny_add_dns_record. An agent can tell what it does and when it is inappropriate without opening the schema.

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 clear procedural guidance: read the record first with bunny_list_dns_records and pass its type, name and value plus any other fields to keep or change. This tells the agent how to use the tool correctly, but it does not explicitly say when not to use it (e.g., for new records use bunny_add_dns_record instead).

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