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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds real behavioral context beyond that: which fields are filterable, that context_str takes a fixed set of context types, and the pagination contract ("pass next_offset as offset") plus the underlying endpoint GET /note.

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?

Three short sentences, front-loaded with what is listed, then filters, then paging. Every sentence carries information; the telegraphic "Paged: pass next_offset as offset" phrasing is slightly terse but not wasteful.

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?

With four optional params, no output schema, and only a readOnlyHint annotation, the description supplies the filter vocabulary and pagination mechanics an agent needs to call it correctly. Minor gaps remain (default sort behavior, whether notes are returned with author/timestamps), and the entity list in sentence one (subscriptions, contacts) does not exactly match the context_str enum (billing_package, user).

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 the baseline is 3, but the description goes further by naming the valid filter fields (context_str values and context_id) — information the schema explicitly defers to the description ("the list tool's description names the valid ones"). That is genuine added value over the structured 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?

States a specific verb and resource ("List notes") plus the entity types notes hang off (customers, subscriptions, invoices, contacts, quotes, items), which cleanly separates it from the create_* and list_* siblings. An agent can identify this as the note-listing tool without opening the schema.

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 enumeration of attachable entities, but the description never states when to reach for this tool versus alternatives (e.g., the create_note sibling) or any prerequisite/limitation. No explicit when/when-not guidance is offered.

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