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 adds meaningful behavioral detail on top: the exact return shape and the critical edge case that publicKeyJwk is null for members who have not finished key setup, meaning they cannot be granted decryption. This is valuable beyond the annotations and compensates for the lack of an output schema.

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 description is compact and front-loaded with the core action, then gives the practical reason to call it, then the return shape and null-key caveat. Every sentence adds information an agent needs, with no fluff or repetition of schema content.

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 simple, read-only listing tool, this is complete: purpose, invocation context, return shape, and an important behavioral edge case are all covered. The schema fully documents the only parameter, and annotations cover the safety profile, so nothing critical is missing.

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 single optional org parameter is fully documented in the input schema, including slug-or-id semantics and multi-org error behavior. The description itself adds no parameter-level detail, so the baseline of 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?

States a specific verb and resource ('List organization members with their public keys') and goes beyond a generic list by tying the result to grant_env, a concrete downstream use. This clearly distinguishes it from sibling list tools like list_groups or list_invites.

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?

Gives a clear when-to-use signal: 'call this when handing a project off to a person.' It explains the purpose of the returned keys in the grant_env flow. It doesn't explicitly discuss exclusions or alternatives, but the intended context is unambiguous.

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