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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds value by specifying the scope (email templates) and the workflow connection, without contradicting annotations. It does not mention any additional behavioral traits, but given the annotations cover safety, this is sufficient.

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?

Two sentences, zero wasted words. The first sentence states the core purpose and pagination; the second gives filtering and workflow guidance. Front-loaded with the main action.

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 list tool with 6 parameters and no output schema, the description covers the core purpose, filtering, and integration with the sibling tool. It does not detail output format, but for a list operation the return type is typically an array, which can be inferred. The description is complete enough for effective 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 coverage is 100% with descriptions for all 6 parameters. The description adds meaning by explaining the purpose of `type` and `q` filters and mentioning pagination. While it does not describe every parameter, the schema already does that, so the description provides contextual value beyond the structured schema.

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 it lists available placeholders for email templates with pagination, and distinguishes from sibling tool hires_prepare_template_placeholders by mentioning it as the next step. The verb 'list' and resource 'template placeholders' are specific and 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?

The description provides explicit workflow guidance: 'Discover placeholders here, then use hires_prepare_template_placeholders to get an HTML tag for insertion.' It also suggests filtering by type and search by label. While it does not explicitly state when not to use this tool, the context is clear enough for an agent to decide.

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