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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description usefully adds the 'scheduled-only' editability constraint, but says nothing about reversibility, whether omitted fields are preserved, or what happens if the post publishes mid-edit.

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 short sentences, each earning its place, with the core action and the hard constraint front-loaded and the patch rule placed last.

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?

Adequate for a concise mutation tool, especially since the 11-parameter schema is fully self-documenting. Still, with no output schema and nested platform-specific objects, the description says nothing about response shape or failure modes, and the patching rule could be stated more explicitly.

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 baseline is 3; the description earns above baseline with 'Only include the fields you want to change,' which establishes patch/partial-update semantics that the schema alone does not convey.

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 specific verb and resource ('Update a scheduled post') and scopes it with a clear precondition. It doesn't name or contrast with siblings like create_post or cancel_post, but the scope makes it distinguishable.

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?

'Only scheduled posts can be edited' is a real eligibility constraint, so usage is implied and bounded. However, it names no alternative workflow (e.g., cancel_post + create_post to change a published post) and gives no guidance on post state transitions.

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