Imessage Search

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

Annotations already include readOnlyHint: true and openWorldHint: false, covering the read-only nature. The description adds valuable behavioral context by warning that message text is untrusted data, which is beyond what annotations provide. This helps the agent know to treat results cautiously, but it doesn't detail other behaviors (e.g., pagination, result ordering).

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 only two sentences. The first sentence states the purpose concisely, and the second sentence adds a crucial security caveat. Both sentences earn their place with no filler, and the purpose is front-loaded.

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 that an output schema exists (as indicated) and all parameters are documented, the description provides the essential purpose and a relevant data-safety note. It does not explicitly mention that filtering by contact or time is available, but those are covered by the schema. The description is complete enough for an agent to understand the tool's function and call it 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 description coverage is 100%, so all parameters (query, limit, contact, days_back) are fully documented in the input schema. The description adds no additional parameter-specific information beyond what the schema already provides, so a baseline score of 3 is appropriate.

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 states a specific verb ('Search'), resource ('iMessage conversations'), and method ('by text content'). This clearly distinguishes it from sibling tools like imessage_links (search for links) or imessage_unread (list unread messages), making it unambiguous what this tool does.

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 purpose implies usage (searching messages by text), but there is no explicit guidance on when to use this tool versus alternatives like imessage_links or imessage_conversations. No exclusions or conditions are provided, so the agent must infer from the context.

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