Read Messages

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

Annotations already declare readOnlyHint=true and idempotentHint=true, covering the safety profile. The description adds the scoping to a specific conversation, which is useful. However, it does not disclose return ordering, pagination, or how attachments are handled beyond the schema's parameter hints.

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 a single, front-loaded sentence with no redundant information. It achieves maximum clarity with minimal words, fully satisfying the conciseness criterion.

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 5 fully described parameters and annotations declaring a safe read operation, the description provides a minimal but adequate overview. However, it lacks guidance on output format, defaults, or how this tool fits with siblings like list-chats, which is notable since there is no output 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?

Schema description coverage is 100%, with each parameter (chatId, start, end, limit, attachments) having a clear description. The tool description adds no additional parameter semantics, so the baseline of 3 is appropriate as the schema does the heavy lifting.

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 specifies the verb-resource pair 'Read message history' and narrows the scope to 'a specific iMessage/SMS conversation', which clearly distinguishes it from sibling tools like send-message or list-chats. It could be more explicit about differentiation, but the core purpose is unambiguous.

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 implies that this tool is for retrieving messages from a specific conversation, but it does not explicitly state when to use it versus alternatives like list-chats or search-notes. No exclusions or comparison guidance is provided, leaving usage context to inference.

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