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

Annotations already mark the tool as idempotent and non-destructive, but the description adds no behavioral detail beyond the verb 'Validate'. It does not explain what happens on success or failure, whether anything is persisted, or what kind of problem report is returned. readOnlyHint is false, adding ambiguity about side effects.

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 concise sentence with no filler, but it is under-specified. It front-loads the main action, yet omits parameter and usage information that the sentence could have reasonably included.

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 no output schema, low schema coverage, and no annotation depth on behavior, this description leaves major gaps: the return format, what constitutes a validation problem, and the meaning of request_id and idempotency_key are all absent. It is a minimally viable starting point but not complete enough for reliable agent use.

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 0%, and the description does not explain any of the three parameters. The required email_type is not contextualized despite its enum values, and request_id and idempotency_key are completely undocumented, leaving an agent to guess their purpose.

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 ('Validate') and resource ('candidate email template') and even names the key facets checked: subject, HTML, and text bodies. This distinguishes it from nearby siblings like preview, read, or publish, though it does not explicitly name an alternative.

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?

There is no guidance about when to call validate versus preview, publish, or rollback, nor any prerequisites or workflow context. The word 'candidate' hints at pre-publish validation, but that is left to inference.

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