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

No annotations are present, so the description must carry the full burden of behavioral disclosure. It only states the core filter (unreplied sent emails) and a use case. It does not disclose how 'no reply' is determined, the scope of emails scanned, the output format, or the effect of optional parameters. This is insufficient for an agent to predict the tool's behavior confidently.

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 concise sentences, front-loaded with the primary purpose. Every word earns its place, and the 'Use when' clause adds practical guidance without redundancy.

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 absence of annotations, output schema, and any schema descriptions, the description must provide more context. It covers purpose and usage but omits parameter semantics, output format, and potential caveats. For a tool with minimal structured metadata, this is incomplete.

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 has two parameters (days, limit) with no descriptions and 0% schema description coverage. The description does not mention either parameter, leaving their meaning and usage entirely implicit. With no schema-compensating information, the agent is left to guess from parameter names alone.

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 'find' and a clear resource 'emails you sent that have not received a reply', which precisely defines the tool's function. It distinguishes itself from siblings like get_inbox or get_sent by focusing on unreplied sent emails. The added 'Use when' phrase reinforces the purpose.

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 a clear usage context: 'Use when someone asks what needs following up.' This is explicit about when to invoke the tool. However, it does not mention alternatives or when not to use it, so it lacks full differentiation from tools like get_sent or catch_me_up.

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