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

Annotations already declare readOnlyHint=false and idempotentHint=false, so the mutation and non-idempotent behavior are known. The description adds no extra behavioral context, such as whether duplicate aliases are allowed, whether existing aliases are preserved, or any side effects beyond the annotation metadata.

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, focused sentence with no filler, making it easy to parse. It is not scored higher because it omits useful usage or behavioral details that would make it more valuable.

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 two-parameter mutation tool with annotations and an output schema, the description is minimally adequate. However, it leaves clear gaps around when to use this tool vs. siblings and what happens on duplicate aliases, so it is not fully complete.

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?

The description itself adds no parameter-level meaning, but the schema has 100% coverage with clear descriptions for both subjectId and alias. This matches the baseline score for a tool whose schema already documents its parameters adequately.

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 action ('Attaches an alias') and a specific resource ('an SMI subject'), so the core purpose is clear. It does not explicitly distinguish this tool from sibling tools like smi_add_subject_surname, but the verb and object are sufficient to identify the intended operation.

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 the many other smi_add_subject_* siblings, nor does it state exclusions or prerequisites. The only prerequisite hint ('from a prior smi_get_subject...') appears in the schema, not in the description.

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