runtime_monitors

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

Annotations already establish readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds real behavioral context beyond that: sampling cadence (~once a second), what the return contains (latest values plus requested history), and a diagnostic interpretation (rising orphan count = leak).

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 dense, front-loaded sentences: metric list first, then return shape and the leak tip. No filler, though the metric enumeration is somewhat long and the 'Returns:' clause slightly duplicates the schema's implied behavior.

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 burden of describing returns, and it does so ('latest values, and a history of the requested monitors'). Combined with the sampling rate and the leak heuristic, an agent has enough to call and interpret the tool; only minor gaps remain (no mention of history length or ordering).

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 the schema already documents both names and session_id. The description touches parameters only obliquely via 'a history of the requested monitors', adding no syntax or format detail. Baseline 3 is appropriate when the schema does the heavy lifting.

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 names a specific resource (performance monitors of a running game) and enumerates concrete metrics: FPS, frame times, node/orphan counts, memory, draw calls, physics, plus custom monitors. That clearly separates it from siblings like runtime_status or runtime_output. It stops short of explicitly contrasting itself with those siblings, so it lands at 4 rather than 5.

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 can infer this is the tool for perf/leak diagnostics, and the closing hint about a rising orphan count signalling a leak suggests a use case. However, there is no explicit when-to-use statement and no named alternative (e.g., use runtime_status for run state).

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