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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: it opens nothing by itself, it returns screen/button/field-level instructions, and the official API is restricted to approved integrations. It does not describe the shape or length of the returned guidance, which is the main behavioral unknown.

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 mechanic and the handoff to cotlet_browser_* are front-loaded and earn their place. The trailing sentence about ResDiary's official API is relevant but phrased awkwardly and reads as an afterthought, and the opening clause about ChatGPT/Claude/any AI agent is 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 guidance tool with no output schema, the description covers what it does, what it returns at a high level, and what to do next. The only gap is not characterizing the returned instructions' format or granularity, which matters since there is no output schema to fall back on.

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 nothing for the description to disambiguate and the baseline of 4 applies. The description correctly implies no input is needed.

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 ("Check open times in the user's own ResDiary account") and clarifies the actual mechanic: it returns step-by-step instructions rather than performing the check. That clarification is essential because the name alone would mislead an agent into expecting live availability data, but the description resolves it clearly.

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 routes the agent: this tool returns the how-to, then the actual work is done with the cotlet_browser_* tools in the user's ResDiary Cloud Browser. That is a concrete alternative and a sequencing rule. It stops short of stating when not to use it (e.g. when the agent already knows the flow), so it is not a full 5.

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