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

The annotations already carry destructiveHint=true, and the description usefully confirms the mutation by stating 'Writes to the donor record' and naming the POST endpoint. It adds no further behavioral context such as permission requirements, whether the note can be edited/deleted afterward, or side effects on the contact's record.

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 with zero filler; the purpose is front-loaded before the endpoint detail, and nothing is repeated from the title.

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 simple create tool with full schema coverage and an existing destructiveHint annotation, the description covers purpose and the fact that it writes. However, with no output schema, it says nothing about what is returned (e.g., a new note id), and gives no error or validation context, leaving a small completeness gap.

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%, so note, type, private, important, contact_id, time_spent and note_date_time are all fully documented in the schema. The description adds nothing about parameter semantics, which is acceptable at baseline 3 given the schema does the work.

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 gives a specific verb and resource ('Add a note to a contact's timeline') plus concrete examples of what a note covers (call, meeting, visit, touchpoint), and names the backing endpoint. This clearly distinguishes it from read-only siblings like virtuous_list_contact_notes or unrelated writes like virtuous_create_gift_transaction.

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?

Usage is implied by the examples of touchpoints, which help an agent recognize the right scenario, but there is no explicit when-to-use/when-not guidance and no mention of the sibling alternatives (e.g., using list_contact_notes to read back notes). Nothing is misleading, but routing is left to inference.

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