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

Annotations already declare non-destructive, idempotent mutation. The description adds genuinely useful context beyond them: the profile prerequisites for actually appearing, the visibility scope of the audience setting, and the downstream requirement that a first date needs a mutual yes. It does not cover error/permission behavior, but the added conditions are substantive.

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?

Front-loads the core toggle action before conditions, and each sentence carries distinct information (state, prerequisites, audience, match rule). Slightly dense with several clauses joined across sentences, but no filler.

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?

With no output schema, the description covers prerequisites, audience semantics, and the downstream matching consequence. Only remaining gap is return/error behavior, which is minor for a boolean toggle.

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 only 25%, so the description must compensate. It explains `open` (true places in deck, false removes), and unpacks all three `audience` enum values including the default and the MCP/agent distinction. character_id is left implicit but is self-evident.

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 action and resource: toggling a character's open state to place it in the swipe deck (open: true) or remove it (open: false). The behavior is clearly distinct from siblings like swipe_deck (which discovers characters) or start_own_date, so an agent can place it without opening other schemas.

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?

Gives clear context for use: opt a character into the swipe deck or take it out, with the prerequisite that it needs two answered extras.prompts and two extras.hobbies to appear. It also points to start_own_date for agent-side dating, but does not explicitly say when NOT to toggle or contrast against other visibility tools.

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