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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description does not need to repeat safety. It adds value by disclosing that the response includes sender account, schedule timestamps, and cancelability, which gives context about the return data. No contradictions.

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?

A single sentence that is concise, front-loaded with the action, and includes the key return fields. No wasted words.

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 simple get operation with one parameter and no output schema, the description covers the return content but omits any explanation of the input parameter ('id'). It also does not mention potential error cases or the meaning of cancelability, though these are not critical. The missing parameter description is a notable gap.

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 0% description coverage, so the description must compensate, but it does not mention the 'id' parameter at all. It does not explain that the tool retrieves a message by ID, leaving the agent without semantic context for the single required input.

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 states a specific verb ('Get') and resource ('scheduled message'), and it differentiates from siblings like hires_get_notification_message by specifying 'scheduled' and listing the return fields (sender account, schedule timestamps, cancelability). This is clear and distinguishable.

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 implies this tool is for fetching a single scheduled message, contrasting with list tools, but it does not explicitly say when to use it instead of other get tools (e.g., hires_get_notification_message) or provide any exclusion conditions. Guidance is implicit rather than stated.

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