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

Leads with 'WRITE:' and explains the visibility model (private staff-only by default, public to the customer portal when is_public is true), that the note id is returned, and that notes cannot be removed with this server. That last point plus the returned id gives the agent the non-idempotent, hard-to-reverse consequences that the destructiveHint annotation only hints at.

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?

Front-loads the operation type and purpose, then layers visibility, return value, and irreversibility, ending with the endpoint. Every sentence carries distinct information with no padding.

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?

Covers what the tool does, its rules, and its return value even though no output schema exists, so nothing an agent needs to invoke it correctly is missing. The added note about deletion limits compensates for the sparse annotation set.

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 all three parameters are already documented in the schema. The description reinforces the is_public default and privacy meaning but adds no new syntax, format, or constraint detail beyond the schema fields.

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?

Uses a specific verb and resource ('add a note to a contact's timeline'), which cleanly separates it from brightpearl_add_order_note by resource type. It never names the sibling, so the differentiation is implicit rather than stated.

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?

Supplies a concrete use case ('record of correspondence') and clarifies visibility semantics that determine how the note is used. It gives no exclusions or explicit alternative calls, but for a simple write endpoint the context is adequate.

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