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

The description states it converts to an HTML tag, which is non-destructive and read-only. Annotations already declare readOnlyHint=true and destructiveHint=false, so the description adds no new behavioral context beyond what is already provided by annotations.

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, well-structured sentence that immediately conveys the tool's purpose. Every word is necessary and contributes to understanding. It is front-loaded and avoids redundancy.

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?

The description is adequate for a simple conversion tool but lacks details about the output format (the HTML tag structure) and does not explain how parameters relate to different placeholder types. Given no output schema, the description could be more complete by specifying the return value. However, the tool is straightforward, so it barely meets minimal completeness.

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% with descriptions for all 6 parameters, so the baseline is 3. The description does not add additional meaning or relationships between parameters; it simply reiterates the conversion action. No extra guidance on parameter selection or usage is provided.

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 clearly states the tool's function: converting a placeholder reference into an HTML tag for email template insertion. It uses a specific verb ('convert') and resource ('placeholder reference'), and the context of email templates distinguishes it from sibling tools like 'hires_list_template_placeholders' or 'hires_create_email_template'.

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 explicit guidance on when to use this tool versus alternatives. The usage is implied from the purpose (preparing HTML for email templates), but there are no when-not-to-use or alternative tool mentions. This leaves the agent to infer context without clear direction.

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