get_runtime

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds value by stating the categories of data returned (parameters, state-machine states, timelines, playback state), but says nothing about session scoping, revision semantics, or staleness of the snapshot.

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 the verb and resource front-loaded and zero filler. The trailing enumeration is dense but each item conveys real content; only slightly list-like in structure.

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?

No output schema exists, so the description carries some of the burden of describing the return value, which it does at a coarse level by naming the four data categories. With three undocumented parameters and no output schema, the definition is adequate but not complete for an agent to call it confidently.

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 0% across three parameters (requestId, sessionId, expectedRevision), and the description explains none of them. In particular, the meaning of expectedRevision on a supposedly read-only call and how sessionId scopes results are left entirely undocumented.

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?

Specific verb ('Read') plus resource ('runtime') with an enumeration of what is covered: runtime parameters, state-machine states, active timelines, playback state. This clearly separates it from mutating siblings like control_runtime and control_playback, though it does not name those siblings explicitly.

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?

There is no explicit when-to-use guidance, no exclusions, and no named alternative. An agent must infer that this is the read-only snapshot counterpart to control_runtime/control_playback rather than being told so, and nothing indicates when get_scene or describe_timeline would be the better choice.

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