Get message context (window + parent)

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

Annotations already mark this as read-only and idempotent, but the description adds substantial behavioral detail: chronological ordering, clamping to [0,50], a 60k-char response budget, the sync-cache limitation, and the caution that returned bodies are user content rather than instructions. There is no contradiction with the annotations.

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?

The description is compact and front-loaded: the core behavior comes first, followed by limits and constraints, then practical caveats. Each sentence adds a useful fact and there is no filler or repetition of schema details.

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?

For a read-only context window tool, this covers everything an agent needs: invocation details, limits, ordering, local-cache reliability, and a security-relevant note about message content. Since an output schema exists, the description does not need to enumerate return fields, and the only minor ambiguity around include_deleted is mostly handled by the schema.

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?

With 0% schema description coverage, the description must carry the parameter meaning and largely does: before/after are counts, clamped, and default 5; message_id is the target. The one gap is include_deleted, whose behavior is never explained beyond its name and default in the schema.

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 starts with a specific verb and target: returns the messages before and after a message_id, plus the parent when it's a quote-reply. This precise scope distinguishes it clearly from sibling tools like read_chat or search_messages without needing to inspect either schema.

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 description makes the tool's use case clear: obtaining chronological context around a specific message. However, it never contrasts with sibling tools or states when not to use this tool, so an agent has to infer routing from the described behavior rather than explicit guidance.

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