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

Annotations declare readOnlyHint=false, idempotentHint=true, destructiveHint=false. The description complements this by disclosing the permission requirement for publish_now (posts:publish), the outcomes of each mode (saved as draft, scheduled, or added to publish queue), and the mandatory prerequisite calls. No contradiction with annotations; it adds useful behavioral context beyond the structured hints.

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 concise and front-loaded: it states the purpose first, then the flow prerequisites, mode semantics, and a compatibility note. Each sentence carries essential information with no redundancy. The structure is logical and easy to scan.

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 complexity (11 parameters, nested publishTargets, no output schema), the description covers core usage (modes, prerequisites, permissions) but omits details on optional parameters like mediaMetadata, idempotencyKey, and workspaceId, and does not describe the return format or error scenarios. It is adequate for basic operation but incomplete for a tool of this complexity.

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 55%, so the description adds value by explaining mode behavior, the socialSetId+publishTargets flow, and text handling (per-platform limits, textOverride). It also clarifies accountId as backward-compatible. However, parameters like mediaMetadata, idempotencyKey, and workspaceId have no description in either the schema or the description, leaving gaps. Still, the description meaningfully enhances the most critical 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 states the tool creates posts for X, LinkedIn, and Threads, with explicit modes (draft, scheduled, publish_now). It uses a specific verb 'creates' and resource 'posts', and distinguishes itself from siblings like xplanner_create_idea and xplanner_publish_post by focusing on post creation. The platforms and modes are unambiguous.

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 to call xplanner_list_social_sets and xplanner_get_platform_capabilities first, provides mode selection logic (draft default, scheduled with scheduledAt, publish_now with permission), and clarifies old vs new client usage (accountId vs socialSetId+publishTargets). This gives clear when-to-use guidance and even mentions prerequisites.

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