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

Annotations already cover the mutation/destructive nature (readOnlyHint=false, destructiveHint=true), so the description's burden is lower. It adds the scheduled/draft scope and implies partial updates ('You can change...'), but does not disclose outcomes such as behavior on published posts, effects of platform-specific overrides, or whether omitted fields are preserved.

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?

Two short sentences with no filler. The action and resource are front-loaded, and the list of changeable fields is compact and readable. Every word earns its place.

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?

The tool is highly complex (9 top-level params, deeply nested platform_configurations for 11 platforms, no output schema), yet the description only covers a few top-level fields. It never mentions per-platform overrides, account_configurations, or partial-update semantics, leaving a significant orienting gap despite a rich schema.

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 78%, so most parameters are already documented. The description simply restates a subset (caption, schedule time, accounts, media) without adding meaning, and it omits platform_configurations, account_configurations, is_draft, and media_urls entirely. It adds no semantic value 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 states a specific verb ('Update'), a specific resource ('a scheduled or draft post'), and enumerates the changeable fields (caption, schedule time, accounts, media). This clearly distinguishes it from sibling tools like create_post, delete_post, and get_post by its action and object, even without naming them.

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?

There is no guidance on when to use this tool versus create_post or delete_post, no mention of alternatives, and no exclusions (e.g., cannot update published posts). The 'scheduled or draft' qualifier provides some scope, but it stops short of explaining when-not-to-use or what to use instead.

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