hints

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

Without annotations, the description fully covers behavioral traits: read-only, no external calls, no auth needed, fully deterministic, returning compile-time constants. 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?

Three succinct sentences: purpose, behavior, usage. No redundancy, efficiently structured.

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?

Adequately covers return values (character limits, flags, vocabulary, CTA rules) and deterministic behavior. Lacks explicit return format but sufficient for a simple tool.

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% with a clear description of 'channel'. The description adds extra context (use platform prefix only), enhancing parameter understanding 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 returns static per-channel metadata like character limits and Markdown support flags. It distinguishes itself from sibling tools by emphasizing read-only, deterministic behavior.

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?

Explicitly advises using hints before composing variant bodies and then using publish or schedule for a valid variant, providing clear when-to-use and when-not-to-use guidance.

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