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

No annotations are provided, so the description carries the full burden. It discloses the scope ('all conversation threads involving a specific sender'), which is useful, but it does not mention return format, whether threads are sent, received, or both, or any pagination behavior. This is minimally viable but not rich.

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, front-loaded sentence with no redundant words. It effectively communicates the tool's core function in under ten words, earning the highest score for conciseness.

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?

For a simple single-parameter read tool with no output schema, this description adequately covers the main purpose and parameter. It lacks usage guidance and output details, but given the low complexity, it is reasonably complete. Slightly more detail about return value or sender matching would push it to 5.

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 input schema fully documents the only parameter, senderAddress, with a clear description. The tool description adds no extra semantic value beyond restating the parameter's purpose. Since schema coverage is 100%, the 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 uses a specific verb 'Get' with a clear resource 'all conversation threads' and adds a precise qualifier 'involving a specific sender.' This distinguishes it from sibling tools like get_conversation_threads, which likely lists threads without the sender filter. The purpose is immediately clear.

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 tool is for retrieving threads when you care about a specific sender, but it does not explicitly state when to choose this over get_conversation_threads or get_conversation_context, nor does it mention any exclusions. This is adequate but lacks explicit alternative guidance.

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