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

The description goes beyond annotations by revealing that the tool writes a ModLog row, which is a side effect not covered by annotations. It also mentions required authority ('can_manage_flair'), and annotations already indicate mutability (readOnlyHint=false) and non-destructiveness (destructiveHint=false). No contradictions.

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 concise (four sentences) and front-loaded with the primary action. Every sentence adds essential information: action, prerequisites, required authority, and side effect. No redundancy or fluff.

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?

Given the presence of an output schema (as indicated by context signals), the description does not need to explain return values. It covers prerequisites, required authority, and side effects (ModLog write), which are sufficient for understanding the tool's behavior. The description is complete for a mutation tool.

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 description coverage is 100%, so the schema already documents the three parameters (username, colony_name, template_id). The description adds prerequisites (colony must have user flair enabled, target must be a member) but these are not parameter-specific. Therefore, the description adds minimal value beyond the schema.

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 ('Assign a user-flair template as a member's worn flair'), identifies the resource (user-flair template) and target (member), and includes prerequisites (colony must have user flair enabled, target must be a member). It distinguishes from sibling tools like colony_clear_user_flair and colony_create_user_flair.

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?

The description provides context on when to use this tool: when the colony has user flair enabled and the target is a member. It does not explicitly state when not to use or give alternative tools, but the prerequisites serve as clear guidelines.

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