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

With no annotations provided, the description carries the disclosure burden and does well: it reveals that buckets are gap-filled, that rolling averages are computed, that trend direction is returned, and exactly what each bucket contains (avg engagement, likes, comments, shares, conversation rate). It omits auth/permission requirements and pagination/limit behavior, keeping it from a 5.

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, front-loaded with the core capability, then output contents, then usage. The final sentence about the scope parameter is somewhat redundant with the schema but is short and earns its place as a hint.

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?

No output schema exists, so the description appropriately explains the returned bucket contents and computation behavior (gap-filling, rolling averages, trend direction). Combined with the fully documented input schema, an agent has enough to call it correctly; only auth and pagination context are 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 description coverage is 100%, so the schema already documents all six parameters including scope, dates, granularity, and rolling_window defaults. The description only restates that scope should be a post_collections.id, adding no new semantic detail beyond the schema.

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 verb and resource ('Get engagement time series for a profile') and immediately specifies the distinctive output features: gap-filled buckets, rolling averages, and trend direction. This clearly distinguishes it from siblings like get_engagement_brief or get_posting_insights.

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?

Says it is 'useful for understanding whether engagement is growing or declining' and explains the scope parameter's purpose, but never states when to prefer this over alternatives such as get_engagement_brief or get_posting_insights, nor any exclusions or prerequisites.

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