mailkite_me

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

Annotations already declare readOnlyHint=true. The description adds useful context beyond that: it explains that sending is blocked until the account is verified, and that an API key (mk_live_…) is required. This enriches the agent's understanding without contradicting the annotations.

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?

Three short sentences, each earning its place: the returned data, the intended use, and the credential requirement. It is front-loaded with the most important information and has no filler.

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, the description covers the important context: the involved resource, verification gating, the use case, and the required API key. It does not list exact response field names, but this is a minor gap since the discovered values are named.

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 schema description coverage is 100%, so there is no parameter ambiguity. The description appropriately focuses on what the credential lookup returns rather than trying to explain nonexistent inputs.

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 exactly what the tool returns: the account behind the credential (email, verification status, and plan). It also ties it to a concrete lifecycle use case (polling verification after register()), which differentiates it from the many resource-specific sibling tools.

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 explicitly says when to use it: 'Use to poll verification state after register()'. It does not name alternative tools or state when not to use it, but for a zero-parameter account-info tool this is clear enough guidance.

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