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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds useful context that the data is authorized and intended for client-side decryption rather than model context consumption. It still does not disclose return format, pagination, or auth flow details.

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?

It is a single front-loaded sentence with no filler, clearly leading with the action 'Retrieve'. The extreme brevity is appropriate for conciseness but borders on under-specification for a tool with three undocumented parameters.

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?

An output schema exists and annotations cover safety, reducing the description's burden. However, all three parameters have 0% schema description coverage, and the description provides no usage criteria or parameter semantics. For a private-chat retrieval tool with required IDs, this leaves substantial gaps.

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 0% across all three parameters (contextId, chatId, before), and the description does not mention any of them. With low schema coverage, the description is expected to compensate, but it provides no parameter meaning or format guidance.

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 gives a clear verb and resource: retrieve authorized chat data for client-side decryption. It also distinguishes the output from model context, which helps separate it from general message-reading tools. However, it does not explicitly name or differentiate from siblings like list_messages or panel_snapshot.

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?

The phrase 'not model context' implies a usage boundary, but the description gives no explicit when-to-use guidance, prerequisites, or alternatives. An agent must infer when this tool is appropriate versus list_messages, panel_snapshot, or other panel tools.

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