hires_update_message

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

With no annotations provided, the description carries the burden of behavioral disclosure. It conveys full-replace behavior and the 'before send time' constraint, which is valuable. However, it does not disclose what happens to omitted optional fields (whether they are reset or preserved), the response format, or any permission requirements. This leaves meaningful gaps for a mutation tool.

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?

The description is concise and front-loaded, using two short sentences to convey the core action and a key constraint. There is no redundancy or 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?

Given this is a 10-parameter mutation without an output schema or annotations, the description provides the essential 'full replace' behavior and timing constraint but omits other important context such as the fate of unspecified optional fields, return values, and error conditions. The high schema coverage compensates for parameter explanation, but behavioral completeness is only partially addressed.

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?

The schema has 100% coverage for all 10 parameters, so the description need not repeat parameter meanings. The only added semantic is the requirement that all required fields must be provided, which is already indicated by the schema's 'required' array. The description adds minimal value beyond 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 clearly states the tool performs a full update/replacement of a scheduled message before send time. The verb 'update' with 'replace' and the specific resource 'scheduled message' precisely define the action, and the phrase 'All required fields must be provided' distinguishes it from partial-update siblings like hires_patch_message.

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 gives important usage context: this is for scheduled messages before send time, and all required fields must be provided. It implies a contrast with partial updates (likely hires_patch_message), though it does not explicitly name alternatives. This is clear but not fully explicit about when-not-to-use.

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