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

Beyond the annotations, it discloses real side effects: management links are emailed to the organiser, a one-time 'take control' link is returned, and a participant-facing link is produced. It doesn't say that repeat calls create duplicate cards (relevant given idempotentHint=false), which is the main remaining gap.

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 the action and outcome, then preconditions, then locale rules — every sentence carries information. The final locale sentence is slightly telegraphic ("names are Russian") but still earns its place.

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 8-parameter, non-idempotent creation tool with no output schema, the description covers what it makes, what it returns, and the critical email dependency, while the schema carries the field-level detail. Only duplicate-creation behavior is left unstated.

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; the description adds genuine value on top by flagging organizerEmail as the one value that must never be fabricated and by explaining the Russian/Hebrew naming convention that governs recipientName.

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 ("Creates a group greeting card") plus the defining mechanic (multiple signers, opens on a set date) and the return value (link to send to participants). This is unmistakably distinct from board_status, list_occasions and suggest_prompts.

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 concrete preconditions and a hard rule: the organiser's email is required, "Ask the person for anything missing; never invent an email," plus locale conventions per brand domain. It stops short of naming sibling tools (list_occasions, suggest_prompts) as the place to source occasion/prompt values, leaving that routing to the schema.

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