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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful behavior beyond that: the URL is one-time and must be followed by polling ucode_login_poll. This is meaningful context for a correct invocation flow.

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 sentences with no filler. The core action is front-loaded, followed by the preferred alternative and the required polling step. 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?

Complete for a no-parameter tool: annotations cover safety, an output schema exists, and the description provides the full usage flow and sibling routing. An agent has everything needed to invoke and continue the login process.

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 tool has zero parameters, so the description need not document parameters. With 0 params the baseline is 4, and the description still clarifies the one-time sign-in URL behavior, which is the only context an agent needs.

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?

States a specific verb and resource: it creates a one-time browser sign-in URL. It also distinguishes itself from the sibling ucode_connect and connects to ucode_login_poll, so an agent can tell what this tool does at a glance.

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?

Gives explicit guidance: prefer the in-card Connect button (ucode_connect) instead, and poll ucode_login_poll(sessionId) until linked. This clearly frames when to use the tool, when not to, and what follow-up is needed.

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