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

Adds substantial context beyond the annotations: asynchronous semantics (immediate runId, background execution), a dedupe rule that returns an existing in-progress run, a ~1-minute cold-start latency penalty, secrets injected as environment variables, and that it runs the last saved version. The annotations already flag destructiveHint=true; the description reinforces this by noting outputs get saved into the notebook, but it never states that existing saved outputs are overwritten, which would fully justify the destructive flag.

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?

Front-loaded with the action and tightly packed with decision-relevant facts; almost every clause carries information. It is on the dense side, with several concerns (execution, versioning, async, dedupe, latency, auth) chained together, which slightly hurts scanability.

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?

Covers the full lifecycle an agent needs: how to start, how to poll (fastero_get_notebook_run), where outputs land (fastero_read_notebook), permissions, error behavior, and latency expectations. With no output schema, the description correctly explains that the immediate return is only a runId.

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 baseline is 3, but the description adds real meaning: projectId scopes both the secrets injected and the permission check, and a notebook outside the project returns 'Notebook not found'. That ties the parameters to observable behavior rather than just restating their types.

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 concrete verb and resource plus scope: 'Run every cell of a notebook once, now, top to bottom, using compute.' It explicitly distinguishes itself from fastero_write_notebook (unsaved editor edits), fastero_schedule_notebook (timetable) and fastero_get_notebook_run (status), so an agent can route correctly without opening any 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?

Names the alternatives and the conditions that select them: use fastero_schedule_notebook for a timetable, fastero_get_notebook_run to poll the outcome, fastero_read_notebook for the outputs once finished. It also states the eligibility rule (owners, admins, editors) and the deduplication behavior for an in-progress run.

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