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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds the return fields and the underlying endpoint (GET /api/v3/sessions), but says nothing about pagination, empty results, or limits.

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 sentences with the returned fields front-loaded and the prerequisite follow-up; nothing wasted. Slightly fragmentary style, but efficient.

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 one-parameter read tool with no output schema, the description covers what's returned and where to get the id, which is sufficient to call it correctly. Pagination behavior is the only notable omission.

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?

The single session_id parameter is fully documented in the schema, including its link to bookafy_list_classes, so the description adds no new parameter detail. Baseline 3 applies when schema coverage is 100%.

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 the resource precisely (attendees of one class session) and even enumerates the returned fields (name, email, phone). It doesn't contrast with siblings like bookafy_list_customers, but the 'session attendees' framing is specific enough to select it.

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?

'Get session ids from bookafy_list_classes' gives an explicit prerequisite and routes the agent to the correct sibling for obtaining the required id. No when-not-to-use guidance, but the usage context is clear.

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