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

With no annotations, the description carries the burden of behavioral disclosure. It states the return fields (session id, user_id, status, last_active_at, expire_at) and the cost (5 tokens), but it does not mention pagination behavior, error conditions, or any potential side effects. The prerequisite to connect is mentioned, but it is more of a usage guideline than a behavioral trait.

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?

The description is four sentences long, front-loaded with the purpose, then the prerequisite, then output fields, and finally cost. Every sentence contributes necessary information without fluff or redundancy.

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?

Given the high schema coverage and the existence of an output schema, the description is reasonably complete. It covers the prerequisite, the connection targeting, and the returned fields. Minor gaps remain around filtering requirements (e.g., user_id vs client_id), but those are already documented in the schema.

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 all parameters already have clear descriptions. The tool description adds the note about passing clerk_instance_id to target a connection, but this is also present in the schema. It does not add substantial meaning beyond the schema, earning the baseline score of 3.

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 opens with 'List sessions in a connected Clerk application,' which clearly identifies the action (list) and the resource (sessions). It distinguishes itself from siblings like clerk.get_session (single session retrieval) by focusing on the plural listing operation.

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 gives a clear prerequisite ('Call clerk.get_connected_accounts first') and explains how to target a specific connection via clerk_instance_id or use the default account. This provides useful context for when to use the tool, though it does not explicitly name alternatives or state when not to use it.

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