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

With readOnlyHint=true and openWorldHint=true already covering safety, the description adds real value by disclosing that Page Insights are only available when the connection has granted read_insights, plus the exact data categories returned. This permission-conditioned behavior is not derivable from the annotations, though it stops short of describing pagination or failure modes.

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 that front-loads the returned data and ends with the read_insights precondition. Every clause carries information an agent needs, and nothing is padding.

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?

There is no output schema, so the description correctly carries the burden of enumerating the return fields (followers, engagement, 28-day views/views/post engagements/daily views) and the read_insights gate. Combined with 100% parameter coverage and read-only annotations, it is nearly complete, missing only error/empty-state behavior.

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 both accountId and profileId are fully documented in the schema, including the list_accounts/list_profiles provenance and the both-must-agree rule. The description adds nothing about parameters, so the baseline 3 applies where structured data does the heavy lifting.

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 ('Return') and a specific resource (a Facebook Page's follower count, engagement, and 28-day Page Insights) and even enumerates the returned metrics. It is clear what the tool does, but it never distinguishes itself from the many sibling insight tools (get_instagram_insights, get_youtube_channel_insights, get_tiktok_account_insights), leaving the platform separation to inference.

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?

It notes the precondition that the connection must have granted read_insights, which is useful context for when the tool will actually return data. However, there is no guidance on when to pick this tool over the platform-specific sibling insight tools, and no exclusions or alternatives are named, so usage is only implied.

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