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

Adds real context beyond the annotations: list params REPLACE rather than append (matching destructiveHint=true), the call uses no credits, and date/time are interpreted in the post's own timezone. The remaining gap is that it never states whether omitted fields are left untouched — a meaningful ambiguity for a partial-update mutation with 10 optional params.

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-loads the resource and precondition, then the risky semantics, then the alternative tool — a sensible order with no filler sentences. The field list at the start partially duplicates the schema property set, which is minor waste but also serves as a quick scan.

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 10-param mutation with no output schema, it covers preconditions, unit/timezone semantics, side effects and the correct alternative tool. What's missing is partial-update behavior for omitted params and any note on what the response contains.

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 80%, so baseline is 3; the description lifts it by clarifying that `date` and `time` are in the post's own timezone, which the schema does not say. The REPLACE semantics it repeats are already in the account_ids and media_file_ids schema descriptions, so that part adds no new information.

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?

Names a specific verb ('Changes') on a specific resource ('an AI Planner post that is still waiting for review') and enumerates the editable fields, so the scope is unambiguous. It also explicitly distinguishes itself from the sibling update_post by state (approved vs. pending review).

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?

Gives an explicit exclusion and the alternative: 'An approved post cannot be changed here (use update_post).' It also sets a precondition ('read the post first') for the replace-style parameters, so the agent knows the required read-before-write workflow.

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