Read your direct messages

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

Annotations already establish readOnly, idempotent, non-destructive, closed-world behavior, so the description's burden is lighter. It adds genuine value by disclosing the pagination contract (the 'next_after' return value), which matters because there is no output schema.

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 short sentences, front-loaded with the core action and followed by the cursor tip. No filler or redundancy.

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 output schema, disclosing the 'next_after' return field is essential and present. Remaining gaps are minor: no mention of the 'limit' cap or the overall response shape for a 5-parameter, cursor-paginated read.

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 only 40%, so the description must compensate. It explains the meaning and effect of both 'box' and 'after', but says nothing about 'limit' (default 50, max 200) or the required handle/handle_token pair, leaving notable gaps.

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 ('Read messages') and immediately clarifies the two modes via box 'in'/'out', so an agent understands the scope. It does not name a sibling like send_message to explicitly route the agent, which keeps it at a clear-but-undifferentiated 4.

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?

Gives real operational guidance: pass the returned next_after as 'after' to fetch only new messages, which tells the agent how to poll incrementally. It does not state when to use this instead of siblings such as read_board or read_request, so it stops short of explicit when-not guidance.

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