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

Annotations only declare destructiveHint=false, so the description carries most of the burden and does well: it discloses the real side effect (members receive the gift around their birthday unless status is hidden), the per-venue fan-out, and the admin requirement. It stops short of describing what is returned or how partial failures across many venues behave.

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 purpose, then permissions, then per-parameter guidance, then the user-confirmation caution. Every sentence adds usable information for a tool this complex; nothing is filler or restatement of the name.

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 7-parameter nested-object mutation with no output schema and thin annotations, the description supplies the operational context an agent needs to call it safely. Missing pieces are minor: templateId's purpose and what happens to the member-facing send schedule on failure.

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 29% schema description coverage the description must compensate, and it does for the highest-risk fields: it explains the localized-string shape of content.name/description, the import_image originalUrl → content.imageUrl linkage, imageAttribution, options.expirationDays, options.advanceSendDays, and the status hidden meaning. It leaves templateId and message semantics entirely to the schema, which is the main gap.

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 (Create) and resource (a birthday gift) and anchors it to a known analog ('the same as saving the Partner Hub's birthday gift form'). It also states the object scope ('applies to every venue of venueIds'), which lets an agent separate it from update_birthday_gift and list_birthday_gifts without opening a 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 prerequisites ('Requires the admin role on those venues') and routes prerequisite sub-tasks explicitly (list_venues for ids, import_image first for a new photo). Adds a caution ('confirm the details with the user before calling this'), though it never states when to prefer update_birthday_gift over creating a new gift.

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