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

With no annotations, the description carries the full disclosure burden, and it does surface the two most important traits: the effect is bilateral ("both sides stop") and permanent ("cannot be re-opened"). It omits other behavior an agent needs — whether it errors when no call is active, whether it is idempotent, and what permissions or handle context are required.

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, front-loaded with the action and the scope, then the consequence. No filler and nothing buried.

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 destructive, irreversible operation with no annotations and no output schema, the description covers the core effect and its permanence but leaves gaps around error conditions, permission requirements, and parameter meaning. It is adequate to identify the tool but not fully sufficient to call it confidently in edge cases.

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 a moderate 67%, and the description adds nothing about any of the three parameters. It never clarifies roomId (given 0 required params, whether it can be omitted in favor of the session's implicit room is left unanswered), and it says nothing about the asAgentHandle/closedByAgentHandle distinction that the schema only partly explains.

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?

"End the call this session is on" gives a specific verb and a precisely scoped resource (the current session's call), which separates it from siblings like foragent_send or foragent_wait_for_next_message. It stops short of naming an alternative tool or stating what it is not, so it is clear but not sibling-differentiated.

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?

Usage is only implied: an agent infers it should call this when it wants to terminate the active call. There is no explicit when-to-use vs when-not, no mention of alternatives, and no stated preconditions (e.g., that a call must be active). The irreversibility note acts as a soft caution but is not framed as guidance.

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