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

With no annotations, the description carries the full burden. It does add genuine behavioral context beyond the schema: the confirm gate and that "both client and coach are notified by the existing flow." However it omits permission requirements, conflict/reversibility behavior, and failure modes for a mutation tool.

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?

Three compact sentences, front-loaded with the core action and the gating constraint, followed by parameter format and side effects. No wasted wording.

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 4-param mutation with no annotations and no output schema, the description covers purpose, the confirm gate, param format, and notification side effect. It still omits what "new time" conflicts do, whether the move is reversible, and any required authorization.

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 moderate (75%). The statement "newStart/newEnd are ISO date-time strings" merely repeats what the schema already declares for both parameters and adds no syntax or format detail beyond it. sessionId and confirm semantics are left to the schema; no net new meaning is provided.

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?

"Move a session to a new time" gives a specific verb (move) and resource (session) that an agent can act on. It is clear but doesn't explicitly distinguish itself from siblings like schedule_session or cancel_session, which also manipulate sessions.

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 parenthetical "(confirm-gated)" implies a two-step usage pattern, but there is no explicit when-to-use guidance, no mention of when to prefer reschedule_session over cancel_session/schedule_session, and no stated prerequisites. Usage must be largely inferred.

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