get_messages

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

Given no annotations, the description carries full burden and successfully discloses that the tool marks the conversation as read, explains paging behavior, and warns that message content is untrusted external data. This is comprehensive.

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 sentences front-load the core purpose, then provide key behavioral details and a warning. No fluff; every sentence 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?

Covers purpose, side effect, paging, and security warning for a 3-parameter tool without output schema. Lacks explicit return value details, but the explanation of response containing 'since' for paging partially compensates.

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?

Adds meaning to 'since' by explaining its role in paging, beyond the schema input description. The schema already describes max_messages bounds, but the description implies the window size triggers paging. Schema coverage 67%.

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 clearly states 'Read one private-message conversation' with ordering (oldest first) and a side effect (marks it read). This distinguishes it from siblings like list_conversations which list conversations.

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?

Explains paging behavior in detail: 'repeated calls without since do NOT page' and how to use the response's next_since. It lacks explicit when-not-to-use or alternatives, but the context is clear enough for usage.

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