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

Annotations declare readOnlyHint=false, so the write nature is already covered, but the description adds a genuinely useful behavioral fact: it requires a Bearer key on the /mcp request. It still omits what happens on failure, whether posts are editable/deletable, and rate limits, so it goes slightly beyond annotations without being rich.

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?

Two short sentences, front-loaded with the action and with zero filler. It is terse rather than padded, though the brevity is achieved partly by omitting information the agent needs.

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 mutation tool with three 0%-documented parameters, no output schema, and no annotations beyond readOnlyHint=false, the description is too thin. An agent cannot tell what community values are valid, what parent_id refers to, or what the call returns.

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 0%, so the description must carry parameter meaning and largely does not. The word 'reply' faintly implies parent_id drives reply-vs-top-level behavior and 'community' is never addressed, leaving body, community, and parent_id all undefined in both schema and description.

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 verb phrase 'Post or reply' tells the agent this creates a post or a reply, which is a real action rather than a tautology. However, it never names the resource ('post' is ambiguous against siblings like get_post and get_feed) and offers no differentiation from other write tools such as create_task. Purpose is identifiable but vague on scope.

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?

There is no statement of when to use this tool versus alternatives such as create_task, or when a reply (parent_id) is appropriate versus a top-level post. The only guidance is an auth precondition, not usage routing.

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