mailkite_list_domains

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

Annotations already declare readOnlyHint=true, so the read-only behavior is covered. The description adds the meaningful prerequisite of a management session token, which is not in the annotations, and clarifies the return includes webhook URL. It does this without contradicting the annotation, so this extra context raises it beyond baseline.

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?

Two short sentences with no filler: the first states the primary purpose and the return content, and the second adds the prerequisite. Every phrase earns its place, and the core action is front-loaded.

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 zero-parameter, read-only list with no predefined output schema, the description covers purpose, the key return field (webhook URL), and the token requirement. It does not mention pagination, ordering, or error behaviors, but the simplicity of the operation makes those gaps minor.

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?

There are zero parameters and the schema is trivially 100% covered, so the description has no parameters to explain. Applying the baseline for a 0-param tool, it earns a 4; there is nothing else the description needed to add.

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: 'List your domains, each with its webhook URL.' It is clearly distinct from sibling tools like get_domain (single domain) or create_domain, and the scope ('your domains') removes ambiguity. The title 'List Domains' is reinforced rather than merely restated.

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 phrase 'List your domains' implies the primary use case, but it provides no explicit comparison to alternatives (e.g., 'for a single domain use get_domain') and no 'when not to use' guidance. The management-session-token requirement adds a precondition but does not help route the agent toward or away from siblings.

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