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

With no annotations, the description carries the full burden and does disclose real behavioral traits: the internal generate→wait→schedule sequence, automatic padding when ratios don't match, and the host-dependent interactive-panel rendering with an explicit instruction not to duplicate its contents. It still omits auth/permission needs, what happens on partial failure, and scheduling constraints.

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?

Front-loaded with the tool's purpose, then the pipeline, then the conditional guidance, then the host-behavior note — a sensible ordering with little filler. The final sentence is dense but each clause carries distinct instructions.

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 complex combined tool with 7 params, no output schema, and no annotations, the description covers the operation flow and rendering behavior well but leaves key invocations underspecified. An agent still lacks semantics for most inputs and any failure-mode or dependency information.

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 only 14% (just 'model'), so the description must compensate for six largely undocumented parameters. It only adds meaning for aspectRatio (4:5/1:1 preference and padding behavior); prompt, caption, accountIds, resolution, and scheduled_at are left with no format, constraint, or intent explanation.

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 uses a specific verb pair and resource: 'Generate an image for a social post and schedule it in one step,' and even spells out the internal pipeline (create image → wait → schedule slideshow post to accounts). This clearly distinguishes it from atomic siblings like create_image and create_post without naming them, though it never explicitly contrasts itself against those alternatives.

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?

Usage is implied by 'in one step,' suggesting it is the combined-operation choice when a user wants both generation and scheduling, but there is no explicit when-to-use vs. when-to-decompose guidance. The only concrete conditional rule ('If any target account is Instagram, prefer aspectRatio 4:5') is parameter-shaped rather than routing guidance.

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