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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is well covered. The description adds the meaningful context that this is the canonical voice source and that remembered copies should not be trusted, but it does not disclose additional behavioral details such as return format or potential errors. With annotations covering the core behavior, a mid-score is appropriate.

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 two sentences with no filler. The first sentence states what the tool provides and its scope; the second gives clear call timing and an important warning. Every phrase earns its place and the key constraint is front-loaded.

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 no-parameter, read-only tool with an output schema and comprehensive annotations, the description is complete. It explains the purpose, scope, timing, application, and authority of the tool, leaving no critical gap for an agent to invoke it correctly.

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 tool has zero parameters, and the schema description coverage is 100%, so there is nothing for the description to add about parameter meaning. The baseline for zero-parameter tools is 4, and the description appropriately focuses on usage rather than parameters.

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 identifies the tool as the source of writing-voice rules for outbound messages, intros, follow-ups, and posts. It uses a specific verb ('get') and resource ('canonical writing-voice rules') and distinguishes itself from siblings like get_instructions by emphasizing it is the single source of truth for the user's voice.

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 explicitly instructs when to call the tool ('BEFORE drafting') and how to apply the result ('apply strictly'). It also warns against relying on remembered or restated copies, which effectively guides the agent to always use this tool rather than cached knowledge. This is strong usage guidance for an agent.

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