prepare_thread

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

Annotations already declare the safety profile (readOnly=false, destructive=false, idempotent=false, openWorld=false), so the description's added value is real: it discloses that a draft is always created, that no LLM is invoked, and the threading chain rule (each later post replies to the preceding confirmed post). That goes meaningfully beyond the structured annotations.

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 tightly packed sentences with the primary action front-loaded, and each subsequent sentence (reply_to behavior, chaining rule, no-LLM note) earns its place by adding a distinct fact.

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 not be explained, and annotations cover safety. The description fills in threading semantics and draft behavior, though the post object format and account parameter remain unspecified, a minor gap for this complexity level.

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% with 3 parameters, so the description carries the burden. It explains reply_to (starts a reply thread) and bounds posts to 1-20 exact text/media, but it never describes the internal structure of the free-form post objects or the account parameter, leaving part of the contract unstated.

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 (stage) and resource (posts/thread) with clear scope (1-20 exact text/media posts for review). The 'always creates a draft' phrasing implicitly distinguishes it from direct-post siblings like post_tweet, but no sibling is named explicitly, keeping it at a strong 4 rather than 5.

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?

It conveys the context (staging posts for review, optional reply thread) but never states when to choose this over prepare_reply, prepare_campaign_messages, or queue_post, nor any prerequisites. Usage is implied through the staging semantics rather than guided.

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