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

Annotations already declare readOnlyHint=true and destructiveHint=false; the description adds meaningful context beyond them by stating it 'opens nothing by itself' and by describing exactly what is returned (step-by-step screens, buttons, fields). The note about the official API being limited to approved integrations explains why a manual guide is needed.

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 core behavior and the handoff to browser tools are front-loaded in the first two clauses. The trailing API-availability note is somewhat tangential but brief and justifies the tool's existence, so it 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?

With no parameters, no output schema, and annotations covering the safety profile, the description supplies what an agent needs: what comes back (procedural steps) and what to do with it. The one remaining ambiguity is what 'W8LIST' actually denotes, which is left unexplained for an unfamiliar agent.

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 takes zero parameters, so there is no parameter meaning to convey; the schema already fully covers this with an empty properties object. Baseline 4 applies.

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 concrete verb and resource ('Read the W8LIST in the user's own ResDiary account') and clarifies the actual deliverable: step-by-step instructions covering screens, buttons, and fields. It distinguishes itself from the cotlet_browser_* tools by positioning them as the follow-up action, though the 'Read the W8LIST' framing slightly oversells it as a data read rather than a how-to lookup.

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 tells the agent when to use it (to learn how to read W8LIST) and what to do next ('then do it with the cotlet_browser_* tools in the user's ResDiary Cloud Browser'). No explicit when-not-to-use case is stated, but the sequencing and the named alternative give clear routing.

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