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

Annotations already indicate readOnlyHint=false (mutation) and destructiveHint=false, so the description doesn't need to repeat that. It adds the constraint that only scheduled posts can be edited, which is useful context beyond annotations. It doesn't describe side effects like media replacement behavior or confirmation, but that's minor given annotations.

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 concise sentences with no wasted words. The first sentence states the action and scope, the second adds a critical constraint. Front-loaded with the core purpose.

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 tool with 6 parameters and no output schema, the description is sufficiently clear for an agent to invoke correctly. It covers the essential constraint (scheduled posts only) and the editable fields. It doesn't explain edge cases like time validation or media replacement, but these are covered by schema parameter descriptions and reasonable assumptions.

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 100%, so all parameters are documented. The description lists the editable aspects (caption, time, accounts, media) but doesn't add meaning beyond what the schema already provides. It doesn't explain partial update behavior (only required post_id), but that's implicit in 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 clearly states the tool's function: changing caption, publish time, target accounts, or media on an existing scheduled post. It distinguishes from siblings like sprkly_schedule_post (creating) and sprkly_delete_scheduled_post (deleting) by specifying it edits existing scheduled posts.

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?

It provides a key usage constraint: only posts with status 'scheduled' can be edited, which tells the agent when not to use it. However, it doesn't explicitly mention alternatives like creating a new post with schedule_post for unscheduled content, though the constraint implies that.

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