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

Annotations already declare readOnly, idempotent, and closed-world, so the safety profile is covered. The description adds genuine behavioral detail beyond that: MAC codes are recognized but deliberately not expanded and are signalled via a mac_code flag, and the output carries G group, P group, serologic equivalent, and flags.

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?

A single dense sentence that front-loads the verb, the input, and the output form, then qualifies the MAC-code caveat at the end. Every clause carries information, though the parenthetical format list is slightly heavy.

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?

An output schema exists, so return values need not be explained, yet the description still summarizes what comes back (2-field form, groups, serologic equivalent, flags). Combined with full param coverage and annotations, an agent has everything needed to invoke it 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 coverage is 100% and there is a single parameter, so the baseline is 3. The description nonetheless adds real value over the schema's generic 'any nomenclature era' by listing concrete accepted forms (A*0101, Cw*07:02, A*02:XX, A*02:01g, optional HLA- prefix).

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 (normalize) and resource (one reported HLA allele name), plus the exact output form (current 2-field form with G/P group and serologic equivalent). This distinguishes it clearly from siblings like allele_info and validate_gl_string, which serve different purposes.

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 scopes usage tightly ('one reported HLA allele name', 'any era or reporting shorthand') and enumerates accepted input styles, which tells an agent when this tool applies. It does not, however, name an alternative or state when another sibling (e.g. allele_info) should be preferred.

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