list_accounts

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

No annotations provided, so description carries full burden. It implies a read-only operation by stating 'discovered from Thunderbird' and describes what is returned (accounts with on-disk store). However, it does not disclose potential side effects (e.g., whether it triggers a refresh).

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?

Single sentence, 12 words, front-loaded with the action verb and resource. No unnecessary information.

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?

Has an output schema, so description does not need to detail return values. Covers essential context (source, what is listed). Could be more precise about the format or limitations (e.g., filter criteria), but given zero parameters, it is sufficient.

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?

No parameters exist in the input schema, so description does not need to provide parameter details. Baseline score of 4 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 specifies the verb 'List' and resource 'incoming mail accounts' with source ('Thunderbird') and additional detail ('with their on-disk store'). This clearly distinguishes it from sibling tools like list_folders, which lists folders.

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?

No explicit guidance on when to use versus alternatives. While the resource name makes it clear it's for listing accounts, the tool would benefit from noting that for folder or mail operations, siblings should be used.

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