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

Adds genuinely useful behavior beyond the readOnly/openWorld annotations: it is a paid, credit-consuming lookup and 'repeated requests may purchase data again', which warns the agent against redundant calls. The problem is that the cost information contradicts itself ('at least 10 Nexscope credits' vs '1 credit per request'), leaving the agent unsure what a call costs.

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 purpose sentence is buried in marketplace boilerplate: a source URL, duplicated pricing statements, 'View Pricing', 'Examples are not guaranteed prices', and 'Actual supplier units are reported per request'. The repeated and conflicting credit figures are noise the agent must filter out.

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 two-parameter read-only search with no output schema, the definition covers the core purpose and cost implications, which is the main thing an agent needs before spending credits. It does not describe what a result contains beyond the implicit event list, nor does it explain pagination behavior for the cursor parameter.

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 parameters are already documented and the baseline is 3. The description adds only the 'by name' framing for the query parameter and says nothing about the cursor parameter or how pagination terminates.

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?

Both the opening line ('Search for events by name') and a later sentence ('Search public Facebook events by name') state a specific verb and resource, so the agent knows it queries public Facebook events. It doesn't distinguish itself from siblings like social_facebook_events, social_facebook_event_details, or social_facebook_profile_events, so it stops short of a 5.

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 guidance and no mention of alternatives, even though nearby siblings (social_facebook_events, social_facebook_profile_events, social_facebook_event_details) cover overlapping ground. The only implicit steer is that this is a name-based keyword search rather than a lookup by ID.

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