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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds real value beyond that by disclosing what is included in each post (reactions, comments, shares) and the cost of one credit.

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?

Two short fragments with zero filler, and the scope is front-loaded ahead of the credit note. It is terse enough that the missing pagination and volume context reads as an omission rather than as intentional brevity.

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 two-parameter read tool with no output schema, the description covers what data comes back and the credit cost, which is the essentials. It omits pagination behavior despite exposing a cursor, and says nothing about volume limits or how many posts are returned per page.

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%, with both url (accepting profile URLs, profile.php?id=, numeric ids, or Page names) and cursor fully documented in the schema. The description adds no additional meaning about accepted URL forms or how pagination via cursor should be driven, so baseline 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?

The description names the concrete resource and scope ('Posts from a profile or Page'), which lets an agent distinguish it from facebook_post (single post) and facebook_profile (profile metadata) by name alone. It stops short of an explicit verb like 'list', but the intent is unambiguous.

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?

There is no when-to-use or when-not-to-use guidance, and no alternative is named. The agent must infer from the name that this is the right tool for a profile's post feed versus facebook_post or facebook_profile, and nothing tells it whether Pages and personal profiles are handled identically.

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