mergeTemplate

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

No annotations are present, so the description carries the full burden. The word 'Merge' implies an operation, but it does not disclose whether this modifies data, returns merged content, or requires specific permissions. The behavior is under-specified beyond the basic merge concept.

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, succinct sentence that delivers the core purpose without any filler. Every word earns its place; no structural issues.

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 and no annotations, the description should clarify what the tool returns or accomplishes. It does not mention whether the result is a string, a saved entity, or something else. The tool is simple, but the lack of behavioral detail leaves the agent guessing about the outcome.

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% (both params have descriptions 'Person ID' and 'Template ID'). The description adds the contextual notion of mail merge, implying template placeholders are replaced with person data, which adds value beyond the schema. Baseline is 3 for high coverage, and this modest extra context justifies a 3.

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 specifies a clear action ('Merge') and resource ('an email template with a person's data'), with a clarifying parenthetical ('mail merge'). It distinguishes from sibling 'mergeTextMessageTemplate' by explicitly stating 'email template', making the tool's purpose unambiguous.

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?

No guidance is provided on when to use this tool versus alternatives. The description does not mention sibling tools like 'mergeTextMessageTemplate' or any exclusions. It merely states what the tool does, not when to choose it.

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