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

Annotations cover the safety profile (write, idempotent, non-destructive, open-world), and the description adds value beyond them: it discloses the return payload (link + ready-to-send messages, important since there is no output schema) and the immutability consequence 'Shared cards can't be edited'. It does not explain what dry_run toggles or the repeat-flag/confirmation flow implied by confirm_repeat.

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?

Two tight sentences, zero padding, with the action and its prerequisite front-loaded before the immutability caveat. Every clause carries information.

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 mutating, open-world, non-idempotent-adjacent tool with no output schema, the description adequately covers what comes back and what cannot be changed afterward. It leaves gaps on the dry_run mode and the repeat-detection confirmation path that confirm_repeat's own hint gestures at, which an agent would need before calling safely.

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% (just confirm_repeat), so the description must compensate. It partially does by establishing card_id's provenance via choose_card and clarifying the share is free, but dry_run and recipient_name receive no explanation in either place, and dry_run is behavior-changing.

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?

Names a specific verb and resource ('Publishes a card ... as a free eCard') and explicitly ties the input to the sibling tool choose_card, so an agent can separate it from order_card or find_cards without opening a schema. It also states the concrete deliverable: the share link plus ready-to-send messages.

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 a clear precondition ('a card chosen with choose_card'), which is genuine routing guidance toward the sibling that must run first. It does not state when-not to use it or how it relates to the other write sibling order_card, so it stops short of full alternative coverage.

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