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

Annotations declare the write, open-world, non-idempotent, non-destructive profile, so the safety bar is largely met by structured data. The description adds genuine value beyond them: the mandatory user-confirmation step and the external expectation that "a partner replies by email within one business day." It does not explicitly warn that repeated calls create duplicate inquiries (non-idempotent), which keeps it out of 5 territory.

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 tight sentences: purpose first, then the gating condition, then the outcome expectation. No filler, no restatement of the tool name or title, and the invocation constraint is front-loaded after the purpose.

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?

An output schema exists, so return values need not be described, and the annotations already carry the safety profile. The description still supplies the two things an agent most needs for a write-to-external-party tool: the confirmation prerequisite and the expected response channel/timeline. Nothing material is 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 100%, so the schema already defines all five parameters including formats and examples for topic. The description only echoes the three required fields as the ones to confirm ("name, email and message"), adding emphasis but no new syntax or semantics. Baseline 3 is appropriate when the schema does the heavy lifting.

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 ("Send a project inquiry to SigmaJunction") plus the acting capacity ("on the user's behalf"). This is unambiguously distinct from every sibling tool, which are all read/list/get lookups (get_company_profile, list_services, read_page, etc.). An agent can select it without opening any schema.

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?

Gives an explicit positive condition ("Only use when the user has asked to contact SigmaJunction") and a required procedural precondition ("confirm the name, email and message with them first"). No sibling performs a comparable send action, so there is no alternative to route to; the when/when-not framing is fully covered.

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