Per-post engagement metrics

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

Annotations already declare readOnly, idempotent, and non-destructive. The description adds valuable behavioral context by disclosing that metrics arrive via periodic sync and recent posts may be empty until the next cycle. This goes beyond the annotations and is important for setting expectations.

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 three sentences long, each adding distinct value: purpose, data freshness caveat, and alternative tool. It is front-loaded with the core functionality and has no redundancy or 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 read-only tool with one parameter and no output schema, the description covers purpose, usage, behavior, and parameter scope. The sync caveat and explicit alternative complete the picture, leaving no significant gaps.

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?

The schema has 100% coverage, with a description for post_ids. The description mentions 'one or more post ids' aligning with the array parameter, but adds no additional formatting or syntax details. Baseline 3 is appropriate.

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 clearly states the tool returns per-post engagement metrics (impressions, likes, comments, shares, etc.) for one or more post IDs. It uses a specific verb and resource, and explicitly distinguishes itself from get_engagement_summary for aggregate data.

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 explicitly directs users to get_engagement_summary for the org-wide aggregate, indicating when not to use this tool. It also notes the periodic sync behavior, helping users understand when to expect data, especially for very recent posts.

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