list_chats

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

With no annotations provided, the description carries the behavioral disclosure burden. It discloses that the operation is a read-style listing, that matching is case-insensitive, and that output is one line per chat with specific fields (ROWID, name, last message time, message count). It does not mention ordering or pagination, but the core behavior is transparent.

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 two tightly written sentences. It front-loads the core purpose, then adds filtering behavior and return format without any filler or redundant schema restatement.

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 tool has only two optional parameters and an output schema, the description covers the important behavioral choices: listing, optional filtering, case-insensitivity, and returned fields. It is slightly incomplete only in not elaborating on what 'recent' means or how 'limit' affects the result, but these are minor given the schema defaults and 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?

The schema itself contains no parameter descriptions (0% coverage), so the description must compensate. It does well for 'query' by explaining case-insensitive substring matching against chat name, contact names, or chat identifier, but it provides no semantics for 'limit' beyond what the parameter name and default already imply.

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 uses a specific verb ('List') with a clear resource ('recent iMessage/SMS chats') and details optional filtering by substring against chat name, contact names, or identifier. It also specifies the output shape, making the tool's purpose immediately 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 clearly implies when to use the tool: when you need a recent chat list, optionally narrowed by a text query. It does not explicitly contrast with sibling tools like search or read_thread, but the listing behavior is stated well enough that an agent would rarely confuse it with those tools.

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