screencast_stop

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

Annotations declare readOnlyHint=false, so the agent already knows this is a write/mutating operation. The description adds that the recording must be "active" and scoped to a target page, but says nothing about what happens to the captured data, what is returned, or behavior when no recording is running.

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?

One short sentence with no filler, front-loading the verb and resource. It is appropriately sized for a trivial single-parameter tool, though it could have used a second clause for the no-active-recording case.

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 simple one-required-param mutation with annotations and no output schema, the definition is minimally adequate. It omits edge-case behavior (no active recording) and whether the recording result is delivered anywhere, which an agent would want to know before calling.

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 pageId parameter is already documented in the schema as targeting a specific page by ID. The description restates the page scoping but adds no format, default, or validation detail beyond the schema.

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 ("Stops") and resource ("the active screencast recording on the target page"), which pairs naturally with the sibling screencast_start. It doesn't explicitly name the sibling as the counterpart, so it stops short of full differentiation.

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: one infers this is called after screencast_start to end capture. There is no explicit statement of when to use it versus alternatives, prerequisites, or what to do if no recording is active.

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