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

Annotations already declare the mutation profile (readOnly=false, destructive=false, idempotent=false), and the description adds meaningful behavior beyond that: 'Only the fields you pass are changed,' which discloses PATCH-style partial-update semantics. It omits the human-approval/auth workflow implied by the approval_id parameter, but the added partial-update detail is genuine value.

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?

Two short sentences with the trigger front-loaded and the partial-update rule second — no filler. It could be marginally tighter, but every sentence 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?

With an output schema present and 100% schema description coverage, the description only needs to supply the trigger and the update semantics — both are covered. The unusual approval_id workflow is left to the schema, which is a minor gap given its security implications.

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 the schema by clarifying that omitted fields are left untouched — directly answering the ambiguity of the many optional parameters. It doesn't explain the status enum values (idea/offered/received) or the approval_id flow, which the schema itself partially covers.

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 conveys a specific action (updating a gift) and reinforces it with a concrete scenario (an idea becoming a gift that was given), so the agent knows this mutates gift records rather than creating or deleting them. It stops short of explicitly differentiating from gifts.create/gifts.delete, but the status-transition framing makes the intent unambiguous.

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?

It gives a clear triggering condition ('when a gift's status or details changed'), which is more than most update tools offer. It doesn't name alternatives or state when not to use it (e.g., for brand-new gifts), so it stops short of full routing guidance.

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