update_post

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

With no annotations provided, the description carries the full disclosure burden. It explicitly reveals the critical quirk — 'This won't actually update the server, but will simulate the update' — which is essential for an agent to calibrate expectations. It does not detail the exact return value or error behavior, but the core non-obvious behavior is honestly surfaced.

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?

The description is two sentences: the first states the primary purpose and the second adds a crucial behavioral caveat. It is front-loaded, concise, and every sentence earns its place with zero filler.

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 simple mock tool with fully documented parameters and no output schema, the description covers the essential purpose and the simulation caveat well. The main gap is that it does not describe what the tool returns (e.g., a fake updated post object), which would help the agent interpret the result, but the provided information is otherwise adequate.

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 baseline of 3 applies per the rubric. The description text adds no additional parameter meaning beyond what the input schema already provides for id, body, title, and userId.

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 description pairs a specific verb ('Update') with a distinct resource ('existing post on JSONPlaceholder'), clearly distinguishing it from sibling tools like get_posts, create_post, and delete_post. The platform context further anchors its role in the API.

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?

No explicit when-to-use or when-not-to-use guidance is provided, and alternatives are not named. Usage is implied by the 'update' verb in the description and the sibling tool set, while the simulation note hints that real persistence is not achievable, but no direct comparison to create_post or delete_post is made.

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