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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds that it reads DNS records, which is consistent. It does not contradict annotations. It adds minimal extra behavioral context (e.g., no mention of authentication requirements beyond the word 'owned'), so it meets the baseline but does not go beyond.

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, concise sentence with no filler. It front-loads the core action and resource, and every word contributes to understanding the tool's purpose and scope.

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 read operation with one parameter and annotations covering safety, the description is quite complete. It states what is read and for which resources. It does not describe output format or error handling, but these are not essential given the tool's simplicity and the presence of an output schema is absent, so the description is adequate.

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 compensate. The description explains the single parameter 'domain' by specifying accepted values ('owned .ton domain or .t.me Telegram Username'), adding meaningful context beyond the schema's plain string type. It does not specify exact formatting (e.g., with or without @) but is sufficient for a single parameter.

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 verb ('Read'), the resource ('DNS records'), and the scope ('for an owned .ton domain or .t.me Telegram Username'). It is specific and not a tautology of the title. It implicitly differentiates from siblings like dns.lookup by requiring ownership, making its purpose unambiguous.

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 a usage condition ('owned' domain or username) but does not explicitly state when to use this tool versus alternatives such as dns.lookup. It implies that this is for owned resources, but it does not name any sibling or give an exclusion. The guidance is present but not explicit.

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