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

Even with readOnlyHint=true and idempotentHint=true, the description adds valuable behavioral detail: the feed is not chronological, it is often a ranked selection, pages can overlap due to pinned posts, and callers must deduplicate by id. This goes well beyond what annotations or the schema reveal.

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 sentences with no filler: the main purpose is front-loaded, followed by critical behavioral caveats and a compact parameter note. Every sentence earns its place.

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 read-only public-feed tool, the description covers what the resource is, access semantics, ordering expectations, pagination pitfalls, and the optional payload-reduction parameters. The input schema already documents the parameters, and annotations cover safety, so nothing essential is missing.

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 100%, so the baseline is 3, but the description adds meaning by grouping projection_preset, data_fields, and item_fields as payload-reduction controlscars and by tying pagination behavior to deduplication by id. This helps the agent understand why those optional parameters exist and when to use them.

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 opens with a specific verb and resource: 'Returns public posts from a user's profile as visible to not logged in users.' This clearly distinguishes the tool from siblings like x_get_post, x_get_user, and x_get_user_highlights by scope, access level, and resource type.

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 provides clear context: use this when you need the public posts on a user's profile as an anonymous visitor would see them. It does not explicitly name alternatives or state when not to use it, which keeps it from a 5, but the context is unambiguous.

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