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

The annotations already indicate readOnlyHint=false, openWorldHint=true, idempotentHint=false, and destructiveHint=false. The description adds no behavioral context beyond the word 'Attaches', such as whether this creates a new employer record, how repeated calls behave, or whether the operation is additive or updates existing data. With only minimal annotation coverage, the description carries the burden of explaining side effects, and it does not do so.

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 a single sentence with no fluff or redundancy, making it concise and front-loaded. It states the essential action immediately. However, given the tool's complexity (8 parameters, many siblings), the brevity borders on under-specification, though this is more a completeness issue than a conciseness flaw.

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?

Despite having an output schema, the description is incomplete for a write operation with eight parameters and many sibling tools. It does not explain what 'attaches' operationally entails, when to use this versus similar tools, or any constraints or required context. The schema covers parameter syntax but not the broader decision-making context an agent needs to call the tool correctly.

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 parameter descriptions are detailed, including examples (e.g., 'e.g. 2019') and instructions ('Ask the user directly if it isn't clear from context'). The description itself adds no parameter information, but the baseline for high schema coverage is 3, and the schema adequately covers semantics. No extra value is provided beyond 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?

The description states a specific verb ('Attaches'), a resource ('an employer'), and a target ('an SMI subject'), so the core purpose is clear. However, it does not explicitly differentiate this tool from the many sibling 'smi_add_subject_*' tools, so an agent must rely on the tool name to disambiguate. This is a clear statement, but not quite the level of explicit sibling differentiation that would earn a 5.

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 provides no guidance on when to use this tool versus alternatives. There are numerous sibling tools like smi_add_subject_address, smi_add_subject_education, and smi_add_subject_employee, but the description does not mention any conditions, prerequisites, or selection criteria. An agent is left to infer usage solely from the tool name and generic 'add' semantics.

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