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

Beyond the annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=true), the description discloses the tool's most important behavioral trait: it never publishes or schedules by itself, returns status 'awaiting_confirmation' plus a confirmation link, and requires the user to open the link and tick each account. It also warns the agent not to treat 'all accounts' as blanket approval and not to confirm on the user's behalf. This far exceeds the baseline set by the 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?

The description is dense and front-loaded with the core purpose, then adds media rules, an alternative, mention syntax, and a clearly labeled SAFETY section. Every sentence carries useful information, but the block is long and could be tightened or lightly structured to make the safety instructions and media constraints easier to scan. Still, there is no filler.

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 an 8-parameter mutation tool with no output schema, the description is unusually complete. It explains the output shape (status 'awaiting_confirmation' plus confirmation link), the user confirmation step, media type behavior, mention requirements, and the non-published precondition. Together with the annotations, an agent has everything necessary to invoke the tool correctly and to communicate the required next step to the user.

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?

The input schema already documents most parameters (75% coverage), and the description adds meaningful rules not in the schema: media composition limits (up to 9 images, one MP4/MOV, one PDF, no mixing PDF with other media), the special meaning of status='scheduled' (requires user confirmation), and the inline mention syntax with real ID requirements. One parameter, timezone, remains effectively undocumented by both schema and description, which prevents a 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?

The description states a specific verb and resource ('Edit the copy, date, time, status or media of an existing post') and adds an important scope restriction ('that has not been published yet'). It distinguishes this tool from siblings like schedule_post, publish_post_now, and upload_media by focusing on existing, unpublished posts and even points to upload_media for a different workflow. An agent can accurately select this tool without opening the schema.

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?

The description gives explicit when-to-use context: the post must already exist and be unpublished. It also names a concrete alternative ('To add a single new file to a post in one step, use upload_media with attach_to_post_id instead') and tells the agent where to get mention IDs (list_profiles, list_company_pages) while forbidding invented IDs. This is strong routing guidance relative to the sibling set.

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