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

With readOnlyHint=false the annotation only tells the agent this is a write. The description adds real behavioral context: the admission chain (enroll then bind_actor), that only listed room actions are accepted, that others are refused, and that room membership does not unlock locked capabilities. That is substantive authorization behavior beyond the annotation.

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?

Three sentences, front-loaded with the admission requirement before the action description. No filler; the 'Being inside a room does not authorize...' line earns its place by closing a likely misreading.

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?

A mutation tool with no output schema, but the description covers prerequisites, authorization limits, and refusal behavior, which are the things an agent most needs. Success/return behavior is left implicit, keeping it just under a 5.

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 schema already documents all four parameters including the action enum-like constraint and the content-as-claim semantics. The description reinforces 'subordinate action' but adds no syntax or format detail beyond the schema. 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?

States a specific verb and resource: 'Perform one subordinate action listed for the room you are inside.' The scope ('listed for the room you are inside') distinguishes it from enter_room/leave_room and from the generic atlas.use, though the jargon 'subordinate action' is somewhat abstract.

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 bracketed prerequisite '[NEEDS ADMISSION: enroll, then atlas.bind_actor]' plus 'Any other action is refused' gives clear when-to-use conditions and preconditions. It does not explicitly compare against near-neighbors like atlas.use or atlas.external_action, so it stops short of a 5.

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