send_message_to_sessions

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=false. The description adds useful context that this is a pop-up notification delivered to active sessions, but omits notable behavior: what happens on retry (non-idempotent duplicates), whether offline/inactive sessions are skipped, and any delivery guarantees.

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 well-formed sentence with zero filler, front-loading the action and target. Nothing redundant or missing for the sentence's scope.

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?

With annotations covering the safety profile and a 100%-documented schema plus an output schema, the description is nearly complete for a simple notification tool. Minor gaps remain around session-state preconditions and retry behavior.

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%, including the message_type enum with a documented default, so the schema carries the parameter burden. The description adds no syntax, format, or constraint details beyond what the schema already provides.

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 (send), resource (pop-up notification message), and scope (one or more active user sessions). An agent can distinguish this from sibling session tools like disconnect_sessions or logoff_sessions without opening the schema.

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?

The phrase 'active user sessions' implies a precondition, but there is no explicit when-to-use, when-not-to-use, or alternative guidance. No mention of how this differs from other session-management siblings or what to do if sessions are inactive.

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