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

Beyond annotations, the description discloses retention (automatic deletion after 24 months), permission requirements (write access, read-only error), source-based visibility filtering for accesses without that source, and why the source should be repeated in the note text.

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?

The purpose and call timing are front-loaded, followed by the rationale and parameter guidance. Despite being moderately long, every sentence adds operational value and there is no redundant restatement of schema fields.

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?

The tool has an output schema, so return-value explanation is unnecessary. The description is complete for a write operation: it covers permissions, retention, source filtering, note quality, and workspace selection.

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 0%, so the description carries the full burden. It explains note content with a concrete before→after example, source semantics including journal_list omission and access filtering, and workspace behavior when only one workspace exists.

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 states a specific verb and resource: writing a note into the workspace change journal, with the explicit operational rule to call it after every change. It also distinguishes the journal from Google Ads' unavailable notes feature and from journal_list via the source-visibility behavior.

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?

It gives clear usage timing (after every change), explains why this journal exists (Google Ads has no notes API, 30-day history limit), and states access prerequisites (write permission; read-only access errors). It also explains how journal_list interacts with the source parameter.

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