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

With no annotations, the description carries the full burden, and it delivers: it discloses that codes expire with the link, attempts are rate-limited, and success verifies the email as well as every competitor under it. These side effects and constraints go well beyond what the schema or name could convey.

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 four sentences with no filler: it front-loads the purpose, then explains the workflow, success criteria, and constraints. Every sentence earns its place.

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 two-parameter tool with no annotations and no output schema, the description is nearly complete. It covers purpose, workflow, side effects, expiration, and rate limits. The only minor gap is that it does not describe the response structure or failure modes, but this is not significant given the tool's simplicity.

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 context that the code comes from the Omniology verification email and is a short code, but the schema already documents length, case-insensitivity, and space/dash normalization for the code, plus a UUID format for agent_id. No significant new parameter-level meaning is added.

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: 'Finish email verification WITHOUT a browser.' It clearly distinguishes this tool from browser-based verification and from siblings like request_email_verification and submit_entry by specifying its exact role in the flow.

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 defines the context clearly: this is the MCP-native path for agents, where the operator reads the code from the inbox and relays it. It also states the success consequence ('submit_entry unlocks'), which tells an agent when this step is needed. However, it does not explicitly name sibling alternatives or state when not to use them.

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