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

Annotations already declare non-readOnly, non-destructive, idempotent behavior, so the safety profile is covered structurally. The description adds a genuinely useful behavioral detail beyond that: passing null clears the note, which tells the agent how to reverse the change without opening the schema.

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?

Two short sentences, front-loaded with the action and then the use cases, with the null-clearing behavior last. No sentence is redundant.

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 two-parameter tool with rich annotations and no output schema, the description covers purpose, usage contexts, and clearing behavior adequately. It does not state whether an update overwrites or merges with an existing note, which is the one remaining ambiguity for a mutation tool.

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 both parameters (including the savedJobId-vs-jobId distinction and the null-clearing semantics) are already fully documented. The description's "Pass null to clear the note" restates the schema's own wording rather than adding new meaning, 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?

The description states a specific verb and resource ("Update the note on a saved job") and no sibling tool competes for note editing, so an agent can route to it unambiguously. It stops short of the 5 bar only because it never explicitly contrasts itself with adjacent saved-job tools like save_job or unsave_job.

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 concrete usage contexts ("add context, track application status, or record follow-up reminders") that tell the agent when this tool is appropriate. It offers no explicit when-not or alternative, but the tool has no real alternative in the sibling list, so the guidance is effectively complete.

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