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

Annotations only carry the generic safety flags (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=false); the description adds substantial behavior beyond them: the draft link works once and expires after 24 hours, email addresses are never stored, and pairings are never revealed to anyone including the host. These are exactly the operational and privacy traits an agent needs before calling.

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 tool's purpose and return value, then carefully ordered caveats (what it does not do, what it stores, link lifetime, privacy). Seven sentences, but every one carries load-bearing information with 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?

An output schema exists, yet the description still usefully states it 'Returns a private link.' For an 8-parameter, single-required-field creation tool with a draft/confirmation workflow, the definition covers lifecycle, privacy, and boundaries completely.

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 description coverage is 100%, so the schema already documents all 8 parameters with examples and constraints. The description only adds a generic note that it 'stores only the names and details given here,' which adds little parameter-level meaning beyond the structured fields. Baseline 3 applies.

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 ('Prepare a draft gift exchange') and clarifies the domain variants (Secret Santa, Kris Kringle, name draw). It also sharply bounds scope by naming what the tool is NOT (does not create the group, send email, or contact anyone), which separates it from the sibling help tool and from the eventual group-creation step.

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?

The description lays out the full usage flow ('the person opens the link, checks the details, adds their own email, and taps Start') and the functional exclusions, giving clear context for when this preparatory tool is appropriate. It stops short of explicitly naming gift_exchange_help as the alternative for questions, so it is clear but not fully routed.

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