stop_recording

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

With no annotations, the description carries the behavioral burden and does well: it discloses the graceful ffmpeg quit that finalizes the file, the pid-based fallback, the returned path and duration, and the MCP Apps review player. It does not cover error behavior for invalid sessions or whether the operation is idempotent, so it stops short of fully transparent.

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 tightly written sentences with zero filler. The core operation is front-loaded, followed by the meaningful behavioral details and client-facing side effect.

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 no-annotations, no-output-schema tool, the description supplies the essential behavioral context: finalization semantics, fallback behavior, and return values. It is nearly complete, with the main remaining gap being invalid-session or failure behavior.

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 100%, so the single parameter is fully documented in the schema as the session id returned by start_recording. The description adds little beyond saying it takes a session id, so the schema is doing the substantive work.

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 ('Stop a recording') and immediately narrows it to stopping by session id. It distinguishes itself from start_recording and other session-related siblings by describing the exact operation and its finalization behavior.

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?

Explains the primary use case (stop an active recording by session id) and gives a concrete condition for the fallback path (lost live handle after a server restart). It does not explicitly say when not to use it or name an alternative tool, but the usage context is clear.

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