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

Annotations already establish readOnly/idempotent/non-destructive, yet the description adds substantive behavior beyond them: no saved post, no reserved quota, no upload, no schedule, no publication, executed inside a rolled-back transaction, plus the shape of the returned issue data. This is exactly the side-effect disclosure an agent needs for a validation 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?

Four dense sentences with zero filler, front-loading the single most important fact (read-only dry run) before the guarantee of no side effects and the return shape. Nothing is repeated from the title or schema.

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 9-parameter tool with nested platform_configurations, the description covers the essential risk question (does this write anything?) and defers parameter detail to a 100%-covered schema and return detail to the existing output schema. Nothing an agent needs to invoke it correctly is missing.

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%, so the schema already documents all 9 parameters (media_ids, is_draft, publish_now, platform_configurations, etc.) in detail. The description adds only the single note that it takes existing media IDs, which mildly reinforces media_ids semantics but adds little beyond the schema. Baseline 3 applies.

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?

States a precise verb+resource ('validate a proposed post' via a read-only dry run of publish-time validation) and immediately differentiates itself from the write siblings create_post/publish_post/schedule_post by declaring it saves nothing. An agent can tell it apart from the write tools without opening any schema.

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 gives clear context for use: run the real publish-time validation path before actually publishing, and it notes it 'takes existing media IDs', implying media must already be uploaded. It never names an explicit alternative (e.g. publish_post/create_post) or states a when-not condition, so it falls short of a 5.

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