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

Annotations flag destructiveHint=true and idempotentHint=false, but the description goes well beyond that: it states the reply CANNOT BE UNSENT, explains the preview-vs-send behavior gated on confirm, discloses the required separate permission, and enumerates unsupported platforms. This is exactly the mutation-cardinality context an agent needs before acting.

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?

Front-loaded with the irreversible-action warning, then confirm semantics, platform support, permission, and ID provenance in a logical order. The platform enumeration is long but each item earns its place by preventing a doomed call; the prose is dense but not redundant.

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 destructive 4-param write tool with no output schema, the description covers safety, permissions, platform scope, parameter provenance, and even the preview return shape. Nothing an agent needs in order to call this correctly is missing.

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 coverage is 100%, so baseline is 3, but the description adds workflow meaning by tying confirm to a preview mode that 'sends nothing at all' and tells the agent where conversationId/accountId originate (soclo_inbox_list). It slightly restates the schema's own confirm/message text, so it is additive rather than fully original.

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 precise verb+resource ('Send a direct-message reply') plus the acting identity ('as the account owner'), which cleanly separates it from siblings like soclo_inbox_reply_comment and soclo_inbox_reply_review. An agent can identify the 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?

Explicit when-to-use rules: pass confirm:true only after owner approval, otherwise a preview is returned. It also names which platforms support replying here versus TikTok/Threads, requires the manage:inbox permission, and points to soclo_inbox_list for the IDs — covering prerequisites, exclusions, and an alternative path.

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