list_templates

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

With no annotations, the description carries the full behavioral burden. It discloses that templates are stored as files, gives the default path and the environment variable override, and describes the return format (dictionary with name and subject). This goes beyond just the action and provides useful behavioral context, though it does not explicitly mention read-only nature or edge cases.

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 concise and well-structured. It front-loads the purpose, then provides storage details and return format in separate lines with clear formatting. Every sentence earns its place 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 there are no parameters and an output schema exists, the description is complete. It explains the storage mechanism, environment override, and the return shape, leaving no critical information missing for an agent to invoke the tool correctly.

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 schema coverage is trivially 100%. The description adds context about the environment variable that affects template location, which is not a parameter but relevant operational detail. Since there are no parameters to describe, a baseline of 4 is appropriate and the description does not need to add more.

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 clearly states the action 'List' and the resource 'all stored email templates.' It distinguishes from siblings like get_template by explicitly saying 'all' and 'stored', implying a bulk listing operation rather than individual retrieval.

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 operational context (file storage location, environment variable override) but does not explicitly state when to use this tool versus alternatives such as get_template or render_template. It lacks any when-to-use or when-not-to-use guidance, leaving the agent to infer the appropriate context.

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