Explain Policy Decision

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

Annotations already mark the tool as read-only and idempotent, and the description reinforces this by labeling it a read-only check. It adds valuable detail by stating that the tool 'identifies applicable grants, denials, creator authority, and storage/model constraints' and by clarifying that it does not execute the action.

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 core behavior is front-loaded in the first sentence, followed by essential context about read-only planning use and a compact, well-organized Args block. Every sentence adds value, especially given the otherwise bare schema.

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 tool with five parameters and no output schema, the description covers purpose, usage context, behavioral boundaries, and all parameter semantics. It does not specify the exact return format, but it offers enough for correct selection and 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 input schema has 0% description coverage and provides only parameter names and defaults, so the description must carry the full semantic burden. The Args block compensates thoroughly by enumerating allowed capability values, storage types, semantic model options, and default behavior for the store parameter.

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 and resource: 'Explain whether the configured owner may perform a proposed action,' and it lists the kinds of constraints the explanation covers. This clearly identifies the tool's function, though it does not explicitly differentiate it from siblings like montycat_policy_view or montycat_policy_history.

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 says this is a 'read-only policy check for planning and diagnostics' and that 'executing the action still requires a separate tool call and fresh engine authorization.' This gives clear when-to-use and when-not-to-use context, but it does not name alternative sibling tools for comparison.

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