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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description nonetheless adds two pieces of non-annotation context: the response includes HTML content, and the call does not spend mail credits — the credit behavior is domain-specific and not derivable from the 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?

Three short sentences, no padding, with the core action and the HTML-content scope front-loaded. The opening 'Get design.' is redundant with the following sentence but costs little.

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?

There is no output schema, so the description carries the burden of telling the agent what comes back; it does name HTML content, which is the most important field, but not the other design attributes. Nothing is said about behavior when the ID is invalid or missing.

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 there is a single nested 'path' object containing an 'id' string. The description conveys that the tool takes a design ID, which is the essential meaning, but says nothing about the nested path wrapper or formats/validation of the ID.

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 and resource ('Get a single design by ID') and adds scope ('including HTML content'). It implicitly distinguishes itself from the sibling listing tool dealmachine_get_mail_designs by saying 'single design by ID', but never names the list tool explicitly.

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?

Usage is only implied: an agent can infer you call this when you already hold a design ID and want the full record, versus listing designs. There is no explicit when-to-use, when-not-to-use, or named alternative.

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