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

Annotations declare a non-read-only, non-destructive, non-idempotent, closed-world mutation, and the description adds real behavior beyond that: the caption is shaped to the tightest caption limit among target platforms, a draft id is returned, and the draft surfaces under /drafts. It does not state that repeat calls create separate drafts (relevant given idempotentHint=false) or any rate limits.

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 sentences with zero filler; the core action comes first and the return/review consequence second. Every clause carries information an agent would otherwise have to infer.

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?

With no output schema, the description usefully states the return value (a draft id) and where the artifact shows up. For a six-parameter creation tool with full schema coverage and safety annotations, the remaining gap is mainly what happens on repeated calls and whether drafts are editable.

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% and the schema already documents every parameter, including the rich post_type enum descriptions and the platform length-ceiling behavior. The description's restatement of the platform limit constraint adds little the schema does not already say, so the 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?

The description names a specific compound action: compose a caption from a content hint and save it as a draft, with the platform-driven length constraint called out. 'Save it as a draft' implicitly separates it from siblings like sprkly_schedule_post, though no sibling is named explicitly.

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 rather than stated: the draft lands under /drafts for user review, which suggests the review-then-schedule workflow. There is no explicit when-to-use or when-not guidance and no named alternative such as sprkly_schedule_post for going straight to a scheduled post.

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