List messages

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

Annotations already declare readOnlyHint=true, so the agent knows this is a read operation. The description adds 'Newest first' (ordering) and 'in a dialog' (scope), which is useful. However, it does not mention pagination, return format, or any other behavioral traits, so it stays at the baseline for annotated tools.

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 short sentences, front-loaded with the core action and a key detail. Every word earns its place with no redundancy or filler.

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?

Despite having a readOnlyHint annotation, the tool has 3 parameters (one undocumented in schema) and no output schema. The description does not clarify pagination, the meaning of accountId, limit semantics, or the shape of the returned messages. This is underspecified for an agent to use confidently.

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 only 33% (only peer is described). The description does not explain limit or accountId, nor does it add meaning beyond what the schema provides. With low schema coverage, the description should compensate but fails to do so.

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 and resource: 'List messages in a dialog.' This clearly distinguishes it from siblings like get_message (single message) or search_messages (searching). The addition of 'Newest first' further clarifies the ordering semantics.

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 provides no guidance on when to use this tool versus alternatives such as search_messages or get_message. It lacks any context about use cases, exclusions, or prerequisites, leaving the agent without clear selection criteria.

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