List sender profiles

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 discloses the machine-local scope, which is a meaningful behavioral trait. However, it doesn't describe the return format, count expectations, or whether profiles are user-managed, leaving the shape of results unspecified.

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?

Two sentences, no filler, each earns its place. The first states the action and scope; the second explains the domain meaning and downstream use. Efficient and front-loaded with the action.

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 parameterless list tool with no output schema, the description covers the essential purpose and downstream coupling well. The only minor gap is not describing the response structure (e.g., list of profile keys/addresses/signatures), but for a zero-parameter, list-only read tool the coverage is strong.

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 tool has zero parameters, so there are no parameter semantics to document. The description focuses instead on the output concept (what a profile entails) and how the output couples to create_letter, which is the appropriate emphasis for a parameterless tool.

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+resource combination ('Lists the sender profiles configured on this machine'), clearly distinguishing itself from siblings like list_locales and list_fonts. It also explains that each profile carries address and signature, adding domain-relevant detail beyond a generic enumeration.

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 implicitly signals usage context (listing profiles to obtain a key for create_letter), which orients the agent on why this tool exists in the workflow. However, it does not provide explicit when-to-use vs when-not-to-use guidance or name alternatives, though the relationship to create_letter provides useful context.

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