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

Annotations already declare this is a non-read-only, non-idempotent write. The description adds genuinely new context beyond them: the reply is public and permanent, and the agent must show the text and obtain user approval first. It does not cover rate limits or whether the reply is immediately visible, but the approval gate is a real behavioral disclosure.

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 action and its consequence before the operational instruction. No filler and nothing repeated from the schema or annotations.

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 three-parameter mutation tool with no output schema, the description supplies the action, the identifier source, and the approval workflow. It omits return/confirmation behavior and any note on whether a reply can be edited or removed afterward, which is a minor gap given the 'permanent' claim.

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 the burden. It explains the origin of reviewId and accountId (list_reviews) but says nothing about 'message' — its 4000-character cap, tone expectations, or whether it supports formatting — leaving one of three parameters undocumented anywhere.

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 ('Post a public reply to a review') with the scope qualifier 'public', which separates it from the sibling reply_to_comment and from generic post-creation tools. An agent can identify the action 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?

Tells the agent where to source the identifiers ('Use reviewId and accountId from list_reviews'), which effectively names list_reviews as the prerequisite step. It gives clear context but no explicit when-not-to-use or failure conditions, so it stops short of a 5.

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