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

No annotations are provided, so the description carries the full burden. It does disclose one meaningful behavioral trait — patch semantics, 'Only the fields you pass are changed' — which is not derivable from the schema. It omits permissions, reversibility of status transitions, and whether SCHEDULED requires a scheduledFor value, so it is only partially transparent for a mutation tool.

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?

Two short sentences, zero waste, and the patch-semantics caveat is front-loaded right after the field list. Nothing could be cut without losing information.

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 5-parameter mutation tool with no annotations, no output schema, and no schema descriptions, the definition is thin. The schema's enums and date-time pattern partially self-document the fields, but the description does not cover required-ness, status transition rules, or the scheduledFor/status dependency an agent must reason about before calling it.

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% across 5 parameters, so the description must compensate. It names four of the five fields (caption, schedule, timezone, status), which maps loosely onto scheduledFor/status/caption/timezone, but adds no enum meaning, no ISO-8601 format hint for the scheduled field, no note that id is required, and no explanation of the null case.

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?

Specific verb (Update) plus resource (a post) and an enumeration of the mutable fields (caption, schedule, timezone, status). It is easily distinguished from create_post/delete_post/get_post by name and description, though it never explicitly contrasts itself with retry_post, the one sibling whose purpose overlaps on 'status changes'.

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?

The second sentence implies the intended usage pattern (partial/patch edit rather than full replacement), which is genuinely useful. However there is no explicit when-to-use vs. when-not guidance: nothing says to prefer retry_post for FAILED posts, whether editing a POSTED post is allowed, or what prerequisites (auth, ownership) apply.

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