gmail_read_thread

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

With no annotations, the description carries the full burden. It indicates a read operation but provides no additional behavioral context such as return format, ordering, error behavior, or any side effects. This leaves the agent with minimal insight beyond the tool name.

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, perfectly front-loaded sentence with no wasted words. It immediately states the action and object.

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?

The tool is simple (one parameter, output schema exists), but because the description lacks usage guidance and behavioral details, it is only minimally complete. The agent can infer the primary purpose but is missing potentially important context about what exactly is returned.

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 coverage is 0%, so the description should compensate. The phrase 'by its thread ID' merely restates the parameter name ('thread_id') and schema title ('Thread Id'), adding no new semantic information such as format, validation, or how to obtain a thread ID.

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 ('Read') and resource ('all messages in a Gmail thread') and identifies the key identifier ('thread ID'). This clearly distinguishes it from siblings like gmail_read_message (single message) and gmail_search.

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 the use case: to read all messages in a thread. However, it does not explicitly contrast with alternatives (e.g., 'use gmail_read_message for a single message'), so guidance on when to choose this tool is only implicit.

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