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

Annotations are all false, so they carry no behavioral signal; the description takes on the full burden and does so thoroughly. It discloses that employee IDs are resolved to logins, out-of-workspace recipients are refused, delivery is immediate, the notification is type 'custom', the sender's name is appended, and record links open on click. This is rich, accurate behavioral context.

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?

The description is front-loaded with the primary purpose and recipient semantics, and most sentences earn their place. The internal detail about type 'custom' and sender-name appending is useful but slightly dense; it could be tightened without losing value.

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 7-parameter write tool with no output schema and non-informative annotations, the description covers the essential invocation path: recipient resolution, workspace restriction, and record linking. Minor gaps remain around error behavior, optional link parameter usage, and the meaning of priority/title/description, but the tool can be called correctly with this description.

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?

With only 57% schema coverage, the description adds meaningful semantics for employee_ids by explaining lookup and workspace validation, and for reference_type/reference_id by describing how the link opens a record. However, it does not clarify the meaning of title, description, or priority beyond what the schema already provides, and the relationship between the optional link parameter and the reference parameters is not fully explained.

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 opens with a specific verb and resource: 'Send an in-app Matrix notification to one or more colleagues in YOUR workspace.' It clearly distinguishes this from system alerts and from sibling notification tools like notifications_get or notifications_delete by framing it as a person-to-person custom message.

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 clear context on when to use this tool: sending person-to-person notifications to workspace colleagues. It also provides cross-tool guidance by directing users to hr_get_employees to resolve employee IDs, and states the workspace restriction. It does not explicitly name alternatives or exclusions, but the use case is well-scoped.

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