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

Annotations already declare destructive=true and idempotent=false, but the description adds concrete consequences: every viewer stops immediately, the broadcast is unresumable, and a later start creates a new broadcast rather than resuming. That is real behavioral context beyond the flags, including the important non-idempotency warning on timeout.

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 tight sentences, front-loaded with the destructive consequence, then exclusions, then failure handling. Every sentence carries distinct information; nothing is redundant padding.

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, non-idempotent, single-parameter tool with no output schema, the description covers effect on viewers, irreversibility, sibling routing, and error recovery. An agent has everything needed to call it correctly and safely.

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?

Only one parameter (projectId) and schema description coverage is 100%, with the schema itself pointing to livereacting_list_projects for the id. The description adds no format or sourcing detail beyond what the schema already provides, so the baseline 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?

States a precise verb+resource+scope: 'End the stream that is currently running for a project.' It explicitly distinguishes itself from livereacting_cancel_schedules (scheduled streams) and livereacting_start_stream, so an agent can disambiguate without opening schemas.

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?

Gives explicit when-to-use context (running stream), when-not-to-use (scheduled streams are out of scope), a social precondition (confirm with the customer if you did not start it), and timeout recovery guidance (call get_stream_status rather than retrying). Nothing is left to inference.

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