When your posts do best

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds the useful fact that results are derived from the user's own account rather than a generic benchmark, but it omits defaults and sampling bounds (90-day window, 500-post read cap) that materially affect results.

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?

A single sentence with no filler, and it front-loads the output shape before revealing the payoff orientation. Every clause 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 five-parameter, read-only tool with no output schema, the description conveys the essential return shape (engagement grouped by hour and weekday). It stops just short of being fully complete by not surfacing default windows or that results are limited to the most recent N posts.

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 100%, so all five parameters are already documented in the schema, including actor, account, timezone_offset_hours and limit. The description adds no parameter-level syntax or format detail beyond what the schema provides, so the baseline of 3 applies.

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?

States a specific resource (your posting times crossed with earned engagement) and the exact aggregation (by hour and by weekday), and frames the question it answers ('when should I post'). This cleanly distinguishes it from sibling analytics tools like get_engagement_summary or get_post_stats, which report aggregate engagement without the time-of-day/weekday breakdown.

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?

Usage is implied by the framing question 'when should I post', so an agent can infer the context. However, it never names alternatives (e.g., get_engagement_summary, get_post_stats) or states when NOT to use this tool, leaving the agent to guess how it differs behaviorally from the other analytics siblings.

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