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

Annotations already flag destructiveHint=true and readOnlyHint=false, so the mutation profile is covered structurally. The description adds genuinely new behavioral context: the operation requires an act key (an authorization requirement) and the reason text is read by the account owner, which affects how the agent should phrase input.

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 short sentences, front-loaded with the action, then the criterion, then the practical requirement. Nothing is padded, and the parenthetical definition of a stream is placed where it is needed.

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 destructive, three-parameter tool with no output schema, the description covers what it does, who is affected, and the key requirement. It stops short of saying what happens to work already logged under the stream or whether the stop is reversible, which would matter for a destructive operation.

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 all three parameters — key, reason, and project — are already documented in the schema, including the note that the owner reads the reason. The description restates that but adds no naming conventions, format, or conditional guidance beyond it, so the baseline of 3 applies.

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 gives a specific verb and resource ("Stop a stream") and immediately defines what a stream is — standing work at a weekly rate — while pointing to stream_set as the tool that created it. An agent can distinguish this from neighbors like work_cancel or stream_set without opening the schema.

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?

The phrase "that no longer earns its place" implies the condition for use (stopping a stream that is no longer worthwhile), which is weak but real guidance. It does not state explicit exclusions, prerequisites, or competing tools such as work_cancel, so the agent must infer when not to use it.

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