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

Despite readOnly/idempotent annotations, the description adds substantial behavior the structured fields cannot: the 150 req/min account-wide rate limit, the 5-second polling floor, the diagnostic precedence for error fields, the precise meaning and limits of tokenExpired (only Instagram reports it; absence is not health), the no-login reality of Custom RTMP/HLS/SRT, and the caveat that LIVE is not proof of delivery. This is unusually rich behavioral disclosure.

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?

Front-loaded correctly: what it reads, then error semantics, then polling, then a closing caveat. It is dense and long for a one-parameter read tool, but every paragraph carries non-redundant operational value, so little is wasted.

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?

There is no output schema, so the description carries the return-value burden and does so fully, naming the status enum, per-destination fields, and derived signals like destinationsNeedingReconnect and notice. Nothing an agent needs to call or interpret it is missing.

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% and the single projectId param already documents its format and points to livereacting_list_projects. The prose adds nothing further about the parameter, so the baseline 3 applies.

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+resource ('Read what a project's stream is doing right now') and enumerates the exact payload (overall status enum, live id, runtime, per-destination status/viewers/peak/times/duration/error). The 'right now' live-state framing implicitly separates it from the sibling analytics tool. An agent can select it 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?

Gives actionable when-guidance for diagnosing failures ('When a destination is failing, read its error field first') and polling cadence ('no more often than every 5 seconds'). It stops short of explicitly routing to or excluding siblings such as get_stream_analytics or validate_destinations, so it is clear context rather than full alternative routing.

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