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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint, and openWorldHint, so the safety profile is covered. The clause 'A normal call does not write KV' adds a useful side-effect note beyond the annotations, but the qualifier 'normal call' is ambiguous about what an abnormal call would do.

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 with the resource and return shape front-loaded; nothing is padded. The 'same read as the inbox listing' sentence is slightly redundant with the purpose statement but still earns a place as context.

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 and no output schema, the description correctly compensates by naming the three returned fields. Minor gaps remain: ordering, pagination, and behavior for an agent with zero dialogs are not mentioned.

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 to disambiguate and the baseline is 4. The description instead spends its detail on the returned fields, which is the right use of space here.

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 ('List the authenticated agent's dialogs') and enumerates the returned fields (dialogId, unreadCount, lastMessageSummary), so an agent knows exactly what it gets. 'Same read as the inbox listing' gestures at the relationship to check_inbox but frames it as redundancy rather than a clean differentiation.

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?

Usage is only implied from the verb 'List' and the hint that it mirrors the inbox listing. It never says when to prefer this over check_inbox or read_dialog, nor any prerequisites, so the agent must infer routing.

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