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

Goes well beyond the annotations (destructiveHint=true, idempotentHint=true) by disclosing cascade semantics ('Roles cascade to descendants unless a child has its own role'), the team-owner protection rule ('Team owners are always admin and cannot be downgraded'), and the admin authorization requirement. There is no annotation contradiction.

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?

Dense and largely waste-free, with each sentence carrying a distinct constraint. The purpose sentence arrives after the scope sentence, which is slightly less front-loaded than ideal, but no sentence is redundant.

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 3-param mutation tool with no output schema, the description covers authorization, cascade behavior, inherit semantics, protection rules, and the return value ('the user's resulting effective_role'). Nothing an agent needs to call it correctly 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?

Schema coverage is already 100%, yet the description adds genuine meaning: 'inherit' is explained as deleting an explicit role and falling back to the ancestor/team-membership role, and it constrains container_id to a team container and user_id to a same-team member. This is value beyond the raw enum. Baseline 3 is exceeded.

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 ('Set or clear a team member's role on a team container') and immediately bounds scope ('Change access only for existing members of the same Hjarni team'). It distinguishes itself from siblings like teams-invite by declaring 'this does not invite anyone or publish a folder'.

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?

Explicitly states the when-not conditions ('does not invite anyone or publish a folder') and the prerequisite ('Caller must have admin role on the target container'). It also names the triggering intent ('Change access only for existing members'), leaving little to inference.

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