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

Annotations already flag this as a non-idempotent, destructive mutation, and the description adds substantial behavior beyond that: published edits go live immediately at the same public URL, design and language are immutable, a verified account is required, and transport-submitted cards only allow title/message/signature changes. It reassures that editing never resends email or alters a dispatch receipt. The one gap is that it never explains what gets overwritten for a draft or what a failed optimistic-concurrency check returns, but overall disclosure is strong.

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-loaded with purpose and then a roughly chronological workflow, which is the right order for an agent reading top-down. It is dense at eleven sentences and some clauses (title/message suggestion etiquette, preview_url display) read as agent instructions rather than tool semantics, but nearly every sentence carries non-redundant 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 an 11-parameter destructive mutation with no output schema, the description supplies the workflow, lifecycle restrictions and permission requirements an agent needs before invoking it. Residual gaps are minor: the meaning of the returned preview_url and revision counter are implied rather than explained, and a few optional parameters remain uncovered by both schema and description.

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?

With only 27% schema description coverage, the description must carry weight, and it does: it explains that design_id must be a currently enabled creative ID, that title is optional while message and signature are required, that recipient details (and by extension recipient_name/recipient_email) are optional for link sharing, that draft_id plus expected_revision drive published edits, and that scheduling details may change before dispatch. It still leaves timezone, scheduled_at format expectations and expected_revision's concurrency semantics implicit rather than stated outright.

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?

Opens with a specific verb and resource: save or update an owned text-only draft or published card, scoped to creative IDs enabled in the MCP catalog. It distinguishes itself from siblings by naming publish_ecard, send_ecard and get_ecard and stating the condition under which each is used, so an agent can route correctly without opening any schema.

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 explicit when-to-use guidance: create or update a draft, then preview and offer publish_ecard or send_ecard; to edit a published card, call get_ecard first and supply draft_id and expected_revision. It also states blocking conditions (pending or unresolved email processing) and what may change at each lifecycle stage, which is unusually complete routing guidance.

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