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

Annotations already declare readOnlyHint=false, destructiveHint=true and idempotentHint=true, and the description is consistent with them. The description adds the account/prerequisite requirement, but for a destructive write it never says that 'set' overwrites/replaces any existing note text, which is the most important behavioral fact an agent needs before calling it.

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?

Extremely tight: one scope line, one prerequisite line, two action bullets. Front-loaded and every sentence earns its place with no filler.

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 3-parameter tool with an output schema, full schema coverage, and annotations, the description covers scope, prerequisite, and per-action intent. The only real omission is the overwrite/replacement behavior of 'set' on an existing note, which is a meaningful gap for a destructive operation.

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 the enum for 'action' is declared in the schema, so the schema carries parameter meaning. The description's only parameter-adjacent statement ('set - Write/update the note') restates the action rather than adding syntax, format, or length constraints for note text; 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?

It states a concrete verb+resource (manage contact notes) and then enumerates the two discrete operations, 'get' and 'set', so an agent knows exactly what surface it covers. The note-oriented resource does not overlap with any sibling tool (get_contact, list_contacts, manage_labels, etc.), so there is no ambiguity about which tool to pick.

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?

The description gives a real prerequisite ('Requires a WhatsApp Business account with notes enabled') which is genuine usage context. However it never states when to use this versus a sibling such as get_contact, nor any exclusion conditions; the action list explains what each action does, not when to choose it.

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