Read chat history

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

Discloses non-obvious behavior: message bodies are truncated to previews unless `full` is set, and explains the rationale. This goes beyond the annotations, which only state read-only and idempotent.

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 redundancy. It front-loads the core purpose and then explains the truncated-body behavior efficiently.

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?

Given the schema fully describes parameters and there is no output schema to explain, the description sufficiently covers all necessary context for invoking the tool correctly.

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 descriptions cover all parameters, so the baseline is 3. The description adds no extra meaning for individual parameters beyond what the schema already provides, though it indirectly ties `full` to truncation.

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 action (reading messages), a specific scope (one chat), and a key ordering detail (newest first). It clearly distinguishes from siblings like search or get_chat.

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?

Implies usage for retrieving a chat's message history, and the truncation note hints at when to set `full`. However, it doesn't explicitly compare with sibling tools like get_chat or search.

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