mailkite_list_routes

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

The annotations already declare readOnlyHint=true, so the safe read-only nature is known. The description adds the requirement of a management session token, which is extra operational context not implicit in the schema. No annotations are declared that contradict the description and no conflicting behavioral traits (e.g., pagination, result size) are hidden.

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 two sentences, with no filler. It front-loads the core operation and then supplies the single important prerequisite. Every word earns its place, making it ideal for an agent to parse quickly.

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 tool with no output schema, the description provides enough: what it does and when it can be invoked. It lacks only detail about the returned data structure, but such detail is often unnecessary for a list command and the readOnlyHint already aligns with a safe read operation. The definition is complete enough for correct invocation.

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?

The input schema has zero parameters, so the baseline is 4. The description adds nothing parameter-specific (there are none), which is appropriate. Since there are no parameters to document, this dimension is fully satisfied by the absence of need.

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 inbound routing rules.' It clearly distinguishes this from siblings like mailkite_create_route and mailkite_delete_route by focusing on the read-only listing of configured rules, and it is semantically different from mailkite_list_route_candidates. An agent can immediately know what the tool does 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?

The description includes the prerequisite 'Requires a management session token,' which is useful usage context. However, it does not specify when to prefer this over alternatives such as mailkite_list_route_candidates, nor does it describe exclusions or conditions around calling it. It implies usage but leaves the decision to the agent.

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