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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does not mention whether the tool supports pagination, what the default limit is, whether results are sorted, or any other behavioral traits. The description only describes the concept of starred messages, not the tool's behavior. This is a significant gap for a tool with no structured 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 a single sentence and is concise, but it is not front-loaded with the action or purpose. It reads more like a definition of the data than a description of the operation. It earns its place in terms of length, but the content is not optimally structured for an agent scanning for purpose.

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's simplicity (2 parameters, no output schema, no annotations), the description is still incomplete. It does not state what the return value is, whether results are ordered, or how pagination works. The 'limit' parameter hints at pagination but the description is silent. An agent would need to inspect the schema and make assumptions to use this 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 50% — only 'chat' has a description. The description text adds no information about either parameter. It does not explain what 'limit' controls, nor does it clarify the format or semantics of 'chat' beyond the schema's 'Restrict to one chat JID.' With moderate coverage and no additional description, the tool fails to add value beyond 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 identifies the resource (starred messages) but lacks a clear verb. The title says 'List', but the description is a noun phrase: 'Messages the account owner starred — usually the things they wanted to keep.' It implies listing but doesn't state it explicitly. It does distinguish from siblings like list_messages by the 'starred' qualifier, but the action itself is only implied.

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?

No guidance is given on when to use this tool versus alternatives. It does not mention that this is specifically for starred messages as opposed to regular messages, nor does it describe any exclusions or prerequisites. The agent must infer usage from the title and the parameter 'chat', which provides no context for when to choose this over list_messages.

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