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

Beyond the annotations (destructive, non-idempotent), it discloses auth requirements (sign-in + Aisle membership), the ordering constraint for age confirmation, and explicitly unsupported fields (guest notes, dietary details) – rich context the structured fields do not carry.

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 action and packs prerequisites, required/optional fields, and unsupported data into three dense sentences with no filler; slightly crowded but every clause 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 a destructive mutation with no output schema, it covers authorization, sequencing, required vs optional inputs, and unsupported data. It does not describe what is returned on success or the effect of omitting wedding_id, a minor remaining gap.

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% (baseline 3), and the description still adds value by clarifying that first/last names are required, phone/email optional, that age_band is an explicit eligibility confirmation, and that age cannot be derived from names or relationships.

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+resource ('Adds a guest to the selected wedding') and scopes it to the signed-in account's wedding, clearly distinguishing it from add_my_event, add_my_accommodation, and update_my_guest.

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?

Provides explicit sequencing prerequisites (age confirmation before collecting name/contact details) and notes age cannot be inferred from names or relationships. It does not, however, name the sibling alternatives (e.g., update_my_guest, list_my_guests) or when to prefer them.

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