members_add_role

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

Annotations already include idempotentHint=true and destructiveHint=false, so the bar is lower. The description adds value by clarifying that re-adding is a no-op and by listing the return shape `{added, user_id, role_id}`. It does not contradict the annotations.

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, well-structured with clear sections, and every sentence provides essential information. It front-loads the purpose and includes only necessary guidance, keeping it highly readable.

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 role-add operation, the description covers the essential context: purpose, usage, alternative, idempotency, and return values. With a high-quality schema and annotations, 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 input schema has 100% description coverage, so the description doesn't need to elaborate on parameters. The description adds no parameter-specific details beyond the schema, which is acceptable for the high-coverage case, 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 clearly states the action: 'Add a single role to a guild member.' It uses a specific verb and resource, and distinguishes itself from related tools by explicitly noting it handles a single role, not the entire role set.

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?

Provides explicit 'When to use' and 'When NOT to use' sections with a concrete example of a targeted role grant, and names the alternative tool `members_modify` for replacing role sets. This gives clear guidance and prevents misuse.

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