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

Annotations already declare this is a non-idempotent, non-destructive, open-world write operation, so the safety profile is covered. The description adds the conditional precondition that mediaObjects is mandatory for image/video formats, but says nothing beyond annotations about auth requirements, immediate public publication, or duplicate-post risk from repeat calls.

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 short sentences, front-loaded with the purpose statement, with zero filler. The format-mapping and media-requirement sentences duplicate schema content, so they are slightly redundant but still brief and scannable.

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?

An output schema exists, so return values need no explanation, and the schema fully covers both parameters including the account ID's provenance. The remaining gap is the absence of any sibling-routing or prerequisite context for a publish action, but the definition is otherwise sufficient to call the tool correctly.

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 client_user_network_id, postFormat constants, and mediaObjects. The description merely restates those same mappings, adding no syntax or format detail beyond the schema. Baseline 3 is appropriate.

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 and resource ("Publishes text, link, image or video posts") and enumerates the supported post formats. This clearly distinguishes it from every sibling, which deal with connections, networks, credits, or video checking.

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?

Provides conditional usage guidance at the format level (postFormat 0/1/2, mediaObjects required only for image/video), which tells the agent how to configure a call. It gives no when-to-use-vs-alternative guidance or prerequisites (e.g., needing a valid client_user_network_id from connections.list, or checking videos before posting).

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