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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, but the description adds valuable specifics: 'Nothing is sent or stored by this server' clarifies side effects, and the personal-data warning adds a privacy constraint beyond what annotations convey.

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 tightly written sentences: the first front-loads the core function and delivery mechanisms, the second adds side-effect and privacy caveats. Every sentence carries essential information with no filler.

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?

Given the presence of an output schema and annotations, the description covers the core behavior, side-effect absence, and a critical data-handling rule. It omits only low-risk details like language or company, which are reasonably self-explanatory from the schema enums.

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 only 20%, so the description must compensate. It does clarify channel meaning (WhatsApp, email, Calendly) and the summary's privacy requirement, but it provides no added meaning for language, company, or project_type, which remain only enum names without further explanation.

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 ('Builds') and resource ('a ready-to-send intro message and a link'), enumerates channel types (WhatsApp, email, Calendly), and clearly differentiates this from sibling get_*/submit_brief tools by emphasizing it produces a draft the user sends themselves.

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 gives clear context that this is a drafting tool and that nothing is sent or stored, which implies usage conditions. However, it never explicitly states when to use this tool versus alternatives like submit_brief, nor does it mention any exclusions, so usage guidance remains partially implicit.

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