replay_autoplay

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

Annotations already declare this a non-read-only, non-destructive, open-world mutation, so the safety profile is covered. The description adds genuine behavior beyond that: both values are read back and verified after writing. It does not say what happens when verification fails (error vs. partial write), which is the key behavioral question for a mutation tool. Minor tension: an explicit state setter reads as idempotent while idempotentHint is false.

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 front-loaded sentence with no filler; the important distinction (explicit set + verify, not a toggle) lands immediately. It is arguably too terse for a 4-parameter mutation, but nothing 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?

For a 4-parameter mutation with no output schema and only 50% schema coverage, the description should say what verification returns and how a mismatch on expected_layout_id surfaces to the caller. It gestures at verification but leaves the result contract and failure behavior undefined.

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 50%: target_id and expected_layout_id are documented in the schema (including the precondition-guard semantics), while enabled and delay_ms have no schema descriptions at all. The description only loosely covers them by saying "autoplay state and supported delay", hinting the delay must be one of the enumerated values, but it never states units interpretation for delay_ms or its default/optional status.

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 and resource: "Set an explicit autoplay state and supported delay", plus the distinguishing note that it verifies rather than blindly toggles. An agent can tell it is a state setter, though the description never relates it to the replay_start / replay_step / replay_stop siblings it obviously overlaps with.

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?

"no blind toggle" implies the right situation (you know the desired state and want a verified write rather than an inverted flip), which is real usage guidance. But no explicit when-to-use / when-not, and no named alternative such as replay_start or replay_stop for simply beginning or ending playback.

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