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

Annotations already declare readOnlyHint and idempotentHint, but the description goes further by detailing what the dry-run actually returns (exact blocker, sanitized HTML, resolved mentions, warnings) and what it does not check (rate limits/quota). This adds significant behavioral context beyond structured annotations.

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 three sentences, front-loaded with the key differentiator ('Dry-run a post WITHOUT creating it'). Each sentence earns its place: what it does, what it returns, when to use it, and a caveat. No fluff.

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 the output schema exists and annotations cover safety, the description is complete: it explains the validation behavior, return contents, and rate-limit exception. It also addresses the main use case and points to sibling tools for limits, making it fully contextual for a complex preview 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 description coverage is 100%, so baseline is 3. The description does not add parameter-specific semantics beyond mentioning that validation matches colony_create_post and that it checks post rules / markdown rendering, but the schema already documents all 11 parameters thoroughly.

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 explicitly states the tool performs a dry-run of a post without creating it, distinguishing it from colony_create_post. It names the exact validation behavior and the returned results (accepted status, blocker code/message, sanitized HTML, mentions, warnings), making the purpose unmistakable.

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 provides explicit usage context: 'Use it to check a colony's post rules and how your markdown renders before spending a create.' It also notes a limitation ('Rate-limit / quota are not re-checked here') and points to alternatives (colony_get_limits / colony_get_me), meeting the when/when-not/alternatives bar.

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