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

Annotations already flag destructiveHint=true and idempotentHint=true, but the description goes beyond them by stating the deletion is permanent and irreversible, describing the recovery path, and disclosing the side effect that chat and Studio no longer use the source. That is exactly the added context the annotations cannot express.

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: the destructive action leads, the irreversibility and recovery follow, and the alternative for temporary exclusion closes. No filler, and the most important warning is front-loaded.

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 single-parameter destructive tool with no output schema and full annotation coverage, the description supplies everything an agent needs: what is destroyed, that it cannot be undone, how to restore, and the non-destructive alternative.

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 there is a single parameter, so the schema already documents that 'source' is a source id obtainable from notebook_get_notebook or notebook_add_sources. The trailing 'DELETE /sources/{source}' hints it is a path id but adds little semantic depth, 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 specific verb ('Permanently remove') and resource ('one source from its notebook'), which cleanly separates it from the many sibling delete tools (delete_notebook, delete_note, delete_artifact). It also names the downstream consequence that chat and Studio stop using the source.

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?

Explicitly routes the agent: use notebook_add_sources or notebook_upload_source to restore, and use notebook_ask with a sources argument when the goal is only to exclude a source from a single answer. That is a clear when-to-use-this vs. when-to-use-an-alternative rule.

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