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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description then adds genuine behavioral detail: what includeStats produces (rewardsGiven / rewardsRedeemed, each with total and last-30-days values). It omits pagination/result-size behavior, 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?

Three sentences, front-loaded with the resource definition before the stats mechanic. Dense but nothing is padding; each clause adds information an agent would otherwise have to guess.

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?

With no output schema, the description usefully enumerates the returned gift attributes and stats shape, so an agent knows what comes back. Completeness is strong for a low-complexity two-parameter read tool; only pagination/limits are undocumented.

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, but the description goes beyond it by expanding includeStats into the concrete fields it adds and their time windows. That is meaningfully more than the schema's terse "Include usage statistics for each item", though orgId handling is left entirely to the schema.

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?

The description names a specific resource (birthday gifts of an organization) and enumerates its facets: applicable venues, message, validity, and delivery timing. It is clearly distinguishable from create_birthday_gift / update_birthday_gift by implication, though it never explicitly frames itself as the read/list counterpart to those write siblings.

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?

"Use it to answer how many birthday gifts have been sent or redeemed" gives a concrete use case that ties the tool to a question type, which is real guidance. It stops short of naming alternatives (e.g. member_stats, dashboard_summary) or stating when this tool is the wrong choice.

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