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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), and the description adds the personal-API-key requirement plus a summary of the shape of the result set. It does not contradict any hint; the only modest gap is that it says nothing about ordering, pagination, or behavior when the member has no direct policies.

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?

Three short sentences: what it returns, where the excluded data lives, and the auth requirement. The scope constraint is front-loaded and nothing is repeated from the schema or annotations.

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 single-parameter, non-destructive read with full schema coverage and no output schema, the description gives enough to select and invoke correctly, including what the returned policies look like. The remaining gap is minor operational detail such as ordering or empty-result behavior.

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?

Schema coverage is 100% and the schema itself supplies the provenance hint ('from list_members'), so the description's job here is minimal. It reinforces the singular 'one member' framing but adds no format or edge-case detail beyond the schema, so the baseline 3 applies.

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 names a specific verb and resource ('List the permission policies granted directly to one member') and enumerates the returned fields (permissions, scope, revision). It explicitly separates this tool from the closely-named sibling list_team_permission_policies, so an agent can distinguish the two without opening either schema.

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 the boundary condition ('granted directly to one member') and names the alternative for the excluded case ('Grants the member inherits from teams are on list_team_permission_policies'), which is exactly the routing decision an agent needs. It also adds an auth prerequisite ('Requires a personal API key'), which affects whether the call can be made at all.

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