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

Annotations already mark the tool as read-only, and the description adds meaningful behavioral context beyond that: it scopes the result to the human principal and explicitly states it cannot approve holds or return approval inbox items. This prevents the agent from expecting approval-related behavior from a status endpoint.

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, with the core purpose first and the critical exclusions immediately after. Every word earns its place.

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 read-only status lookup, the description covers who the status belongs to and what it does not include. It lacks an explicit note about the shape of the returned status value, but no output schema exists and the purpose is simple enough that this is a minor gap.

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 the baseline is 4. There is no parameter meaning to clarify, and the description appropriately focuses on scope and return behavior instead.

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 identifies the resource as the subscription or trial status of the human principal who owns the agent, which is more specific than the tool name alone. It also distinguishes itself from approval-related tools by explicitly stating it does not return Approval Inbox items or approve holds.

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 gives clear context for when this tool is appropriate: checking the human principal's subscription or trial status. It provides useful exclusions (no approval inbox, no approving holds) that prevent misuse, though it does not explicitly name sibling alternatives like get_approval or get_agent_status.

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