postfast-mcp

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

With no annotations provided, the description carries the full burden of behavioral disclosure. While it mentions batch creation limits (up to 15 posts) and scheduling capabilities, it doesn't disclose critical behavioral traits like whether this is a destructive operation, what permissions are required, rate limits, error handling, or what happens when posts fail. For a complex creation tool with no annotation coverage, this leaves significant gaps in understanding the tool's behavior.

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 appropriately concise with two sentences that efficiently convey the core functionality. The first sentence states the primary action and batch capability, while the second adds important context about targeting. There's no wasted language, though it could be slightly more structured by separating batch limits from scheduling information.

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 complex mutation tool with 4 parameters, nested objects, no annotations, and no output schema, the description is incomplete. It doesn't explain what the tool returns, error conditions, side effects, or important behavioral constraints. The description provides basic purpose but lacks the contextual richness needed for an agent to understand the full implications of using this tool, especially given its complexity and mutation nature.

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 the schema already documents all parameters thoroughly. The description adds minimal value beyond what the schema provides - it mentions batch creation (implied by the posts array) and targeting specific accounts (implied by socialMediaId), but doesn't provide additional semantic context about parameter relationships or usage patterns. The baseline 3 is appropriate when the schema does the heavy lifting.

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 purpose with specific verbs ('Create and schedule social media posts') and resource ('social media posts'), and distinguishes it from siblings by mentioning batch creation up to 15 posts and targeting specific social accounts. It provides concrete scope that differentiates it from tools like list_posts or get_post_analytics.

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 implies usage context by mentioning batch creation and targeting specific accounts, but doesn't explicitly state when to use this tool versus alternatives like upload_media or generate_connect_link. It mentions the need for social account IDs from list_accounts and media keys from get_upload_urls, providing some prerequisite guidance, but lacks explicit when-not-to-use instructions or clear alternative scenarios.

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