create_post

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

Annotations only declare openWorldHint, so the description carries most of the load and does add real value: pay-per-use credit consumption, an approximate per-post cost, a surcharge when the text contains a URL, and a pointer to current pricing. It also implies upload side effects for media_files ('uploads for you'). It stops short of describing failure modes or what post-creation returns.

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 dense sentences, no filler, with purpose and the reply/media affordances front-loaded and the cost/precondition caveats last. Slightly packed with parenthetical detail but nothing that fails to earn its place.

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 10-parameter, no-required-parameter mutation tool with a nested poll object and no output schema, the description covers the operationally critical unknowns: cost, confirmation precondition, and media sourcing. Parameters like poll, reply_settings, quote_post_id, and the AI/partnership disclosures are left entirely to the schema, which is acceptable at 90% coverage.

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 90%, so the schema already documents nearly all ten parameters. The description adds only a light gloss: that reply_to_post_id is the reply mechanism, and that media_files uploads on the caller's behalf versus media_ids referencing existing uploads. That is a modest increment over the schema, matching the baseline 3.

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?

States a specific verb+resource (publish a post) plus the acting scope (as the given account) and a second mode (reply via reply_to_post_id). An agent can distinguish this from siblings like create_thread, delete_post, or post_action without opening any 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?

Gives an explicit gating precondition: 'Only call when the user has confirmed the exact text and account.' It also clarifies the reply use case. It does not, however, route the agent among alternatives such as create_thread for multi-post threads or upload_media for pre-staged media.

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