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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is known. The description adds the specific fields returned, which is behaviorally useful and goes beyond annotations. It does not contradict annotations and does not conceal any side effects, as this is a simple read operation.

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 a single, well-structured sentence that front-loads the action and lists the output fields. No wasted words or redundant information. It is ideal in length for the tool's simplicity.

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 is no output schema, the description explicitly enumerates the fields returned, which is crucial for an AI agent. It also mentions the optional filter parameter and its purpose. It does not address pagination or limits, but for a simple list tool with one optional parameter, the information is sufficiently complete for correct invocation.

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 single parameter app_id is fully described in the schema as 'Optional filter by attached app' (schema coverage 100%). The description does not add any extra semantic detail about the parameter beyond what the schema provides. Baseline 3 is appropriate since the schema does the heavy lifting.

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 states a specific verb ('List') and resource ('AI agents on the user's account'), and enumerates the returned fields (id, name, role, status, FineMail address). This clearly distinguishes it from siblings like list_agent_tasks or list_apps, which target different entities.

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 purpose is immediately clear: this is the tool for listing agents. While it does not explicitly name alternatives or exclusions, the context (sibling tools like create_agent, list_agent_tasks) implicitly defines its scope. There is no ambiguity about when to use it, but it stops short of explicit when-not guidance.

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