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

Annotations already declare readOnly/openWorld/destructive hints, so the safety profile is covered. The description adds real value beyond that: it flags the data is cached, warns 'Snapshot edges may be incomplete,' and states 'no match does not prove no relationship or ownership' — an important false-negative caveat — plus an 'OAuth-safe' note.

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?

Four short sentences, front-loaded with the purpose and then the selector constraint and the caveat. No filler. Slightly dense but 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?

An output schema exists, so return values need not be explained. Combined with the annotations, the description covers purpose, selector semantics, and the freshness/negative-result caveats. Only connection_context and the relationship to sibling lookup tools are left unaddressed.

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 0%, so the description carries the full burden. It documents the four selector parameters (business_id, ad_account_id, page_id, fb_user_label) and, crucially, the mutual-exclusivity rule that the schema cannot express. It omits connection_context, which is the only unexplained parameter.

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: 'Read cached BM links.' It is distinguishable from list-type siblings like assets_list_businesses and assets_list_pages. The 'BM' abbreviation is jargon, but the resource is otherwise clear.

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?

Gives strong invocation guidance ('Choose exactly one' of the four selectors, 'never combine an asset ID with an FB user'), which mostly belongs to parameter semantics. It never says when to prefer this tool over sibling lookups such as assets_pick or assets_list_businesses, so the when/when-not guidance is implied at best.

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