list_available_accounts

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds valuable context: results are stable, non-secret, and the tool never asks for credentials in chat, plus the empty-result fallback. This goes beyond annotation basics.

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?

Three sentences deliver purpose, usage rules, and error handling with zero redundancy. Every sentence earns its place, and the description is front-loaded with the key action and subject.

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?

With no parameters, an output schema present, and complete annotations, the description fully covers what an agent needs: what the tool does, how to interpret results, and how to handle empty results. No significant gaps remain.

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?

Tool has zero parameters, and the schema coverage is 100% (empty properties). The description correctly omits parameter details. Baseline 4 is appropriate since there is nothing to document.

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 ('List') and resource ('configured accounts') with a clarifying qualifier ('stable non-secret capability records'). This clearly differentiates it from sibling tools like list_mailboxes and list_allowed_recipients, which serve different purposes.

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 explicitly states how to use the results (accounts with can_receive=true for mail reads, can_send=true for send_email) and provides guidance for the empty-result case (instruct user to run UI/CLI, never ask for credentials). It does not explicitly compare to alternative tools, but the usage context is clear.

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