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

Annotations already mark it as mutating, non-destructive, and idempotent; the description adds valuable behavioral context about scoped updates and the 'overwritten uniformly' consequence. It also discloses the dashboardUrl return value and the required content/mediaUrls condition. No contradiction with 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?

Three information-dense sentences, front-loaded with the core action and requirement before scoping details. Examples are brief and directly clarify behavior rather than padding.

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 6-parameter update with one required field, the description covers the required precondition, optional scoping parameters, default behavior, and return value. Nothing needed to call it correctly is missing.

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?

With 0% schema description coverage, the description carries the burden and does well: it explains the content/mediaUrls requirement, platform semantics, channelName selection, and default behavior. postId is inferable from the schema, but clientRequestId is left unexplained, so it is not a perfect 5.

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?

Opens with 'Update an existing draft post'—a specific verb and resource—and clearly frames the operation as modifying an already-created draft rather than creating or deleting. The platform/channel scoping details further distinguish it from sibling tools like create_post_draft and delete_draft.

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?

Gives explicit conditions: platform narrows the update to one provider, channelName further narrows it to one account, and omitting both overwrites all providers uniformly. It does not explicitly name sibling tools or state when to prefer create_post_draft, so it stops short of a full when-to-use vs alternatives statement.

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