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

Annotations only indicate readOnlyHint=false, so the description's statement that it 'Writes an audit-ledger decision event' adds meaningful side-effect transparency. But it does not disclose return format, failure behavior, or authorization requirements, leaving important behavioral aspects unaddressed.

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 terse sentences with no filler. The first sentence names the domain ('Gateway decision point'), and the second specifies the exact decision being made. Every phrase 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?

This is a complex 17-parameter authorization tool with no output schema and minimal annotations. The description fails to explain what the tool returns (e.g., a decision boolean, reasons, or error details), how to handle failures, or which parameters are essential beyond the required list. The description is insufficient for reliable 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?

With 17 parameters and only 12% schema description coverage, the description should compensate by explaining parameter meanings. It loosely maps to agent_id, user_id, and tool ('this agent', 'this user', 'this tool'), but offers no detail on the many other parameters like max_cost, max_risk, or action.

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 tool's function: to decide whether an agent may call a given tool for a specific user at the current time. The verb 'Decide' plus the specific resource ('whether this agent may call this tool') distinguishes it from sibling tools like route_task or get_gateway_options.

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 clear context for use: before invoking a tool, to verify permission for a specific agent/user/payload. However, it does not explicitly mention alternatives or when-not-to-use cases, stopping short of the highest tier.

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