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

Annotations already cover read-only, non-destructive, and idempotent behavior. The description adds the scope nuance (connected user or external provider user ID) but does not disclose pagination, rate limits, or return-shape details. This is acceptable given the annotations but not especially rich.

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 sentences with no filler. The first sentence states what the tool does and the second gives the practical workflow, front-loading the main action.

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 read-only list tool, the description covers its main purpose and the downstream use of post_id. It omits details about pagination or return format, but the annotations and schema cover the essential safety and parameter context.

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 roughly 67%: user_id and account_id are well described in the schema, while offset is not. The tool description reinforces the user_id meaning but adds no parameter-level detail, especially for offset.

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 names a specific verb and resource: listing posts authored by the connected user or a provided user ID. It also states the operational purpose (locating a recent post to get its post_id), which distinguishes it from sibling post-reading and post-writing tools.

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 description gives a clear workflow context: use this before reading comments/reactions or replying, because it supplies the post_id. It does not explicitly name alternatives or when not to use it, so it stops short of the top score.

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