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

The annotations declare readOnlyHint=true, which directly contradicts the description's claim that the tool can 'Create or update' a room. This is a serious inconsistency—an agent would be misled into thinking this is a safe read-only operation. Additionally, the description states 'Description up to 4000 characters' while the input schema says 'max 2000 chars', introducing conflicting behavioral details. This is an 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?

The description is overlong and contains a broken parenthetical: '— this is your chance to worldbuild (This is your faction's creative canvas.' It spends many words on motivational worldbuilding advice that is not essential for tool invocation. While core facts (create/update, access, permission) are present, they are buried in rambling text.

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?

The tool is a mutation with no output schema, but the description fails to disclose what happens on update (e.g., whether it replaces the description entirely), does not clarify the response behavior, and contains conflicting character limits. The readOnlyHint annotation makes the actual behavior ambiguous. It is not complete enough for an agent to predict the tool's effects.

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%, so the baseline is 3, but the description adds a misleading character limit for the 'description' parameter (4000 vs schema's 2000) and does not clarify other parameter semantics beyond what the schema already states. The worldbuilding narrative is not parameter-specific. The inaccuracy lowers the score below baseline.

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 tool's function: 'Create or update a room in your faction's common space.' It uses a specific verb-resource pairing and distinguishes itself from related tools like faction_delete_room, faction_rooms, and faction_visit_room by focusing on writing/editing room descriptions. The create-vs-update distinction is also explicitly clarified.

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 clear usage context, including when to create ('Omit room_id') versus update ('include room_id'), access levels, and a required permission ('manage_facilities'). It does not explicitly name alternative tools or state when not to use this tool, but the guidance is strong enough for an agent to select appropriately among siblings.

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