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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered, and the description usefully adds an authorization prerequisite the annotations do not carry ('requires a personal API key that can read permission policies'). The idempotentHint=false is odd for a listing operation, but the description does not contradict it, and it omits any note on pagination or result size.

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, front-loaded with what the tool returns before the usage and auth notes. Every clause adds information, though the return-field enumeration and the example make the first sentence fairly dense.

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, no output schema, and read-only annotations, the description carries the remaining burden well by describing the fields each permission entry exposes and the credential required. It stops short of covering pagination or ordering behavior, which would matter for a full permission catalog.

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 takes zero parameters, which is the baseline-4 case; there is nothing for the description to disambiguate. The schema itself has no properties, so no semantics are missing or misrepresented.

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?

It names a specific verb and resource ('List every permission key this deployment knows') and enumerates what each entry conveys, so the agent knows exactly what this returns. It does not, however, explicitly distinguish itself from nearby siblings such as list_roles, list_member_permission_policies, or list_team_permission_policies, so sibling differentiation is left to inference.

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?

It states a concrete use case - mapping a person to the right grant, with a worked example ('pipeline.write at pipeline:<key> for a team that owns a delegated pipeline'). That is clear context for when to reach for it, but it names no alternatives or exclusions, so an agent cannot tell when to prefer it over the policy/role listing tools.

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