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

Goes beyond the readOnly/idempotent annotations to explain what the tool does NOT do: 'Chet sends nothing until they open it.' It also lays out the homeowner-side steps (answer questions, add email, confirm by email) so the agent knows the handoff is not complete at the call. No mention of link expiry or what the returned URL looks like, which keeps it off a 5.

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 sentences, front-loaded with what the tool produces, then when to use it, then the handoff mechanics. Every sentence adds decision-relevant information; nothing is repeated from the schema or annotations.

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 two-parameter link-builder with no output schema, the description covers what is returned (a link), the eligibility condition, and the downstream flow. Only minor gaps remain, such as what happens with a link that is never opened or how long it stays valid.

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%, so the schema already fully documents both zip and project. The description reinforces the 'project' concept and quotes its example framing ('already filled in'), but says nothing about the zip parameter or its 5-digit US constraint. Baseline 3 is appropriate.

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 concrete action (builds a link) and the exact resource it produces (Chet's request form pre-filled with the homeowner's project). The siblings get_cost_guide and how_chet_works are informational tools, and this is clearly the action tool, so an agent can route without opening a 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?

Names an explicit trigger condition ('when someone in the United States wants written quotes from local contractors for a home project'), which doubles as an exclusion since the US scope is stated. It does not name an alternative tool to pick instead in edge cases, but none of the siblings are true substitutes.

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