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

Annotations only cover safety flags, but the description adds rich behavior: it does NOT send the request, it returns confirm_url for the homeowner to send, the link expires in 30 minutes, up to three contractors confirm, and it handles the qualified=false branch. It also sets naming constraints, which is unusually useful context.

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?

Front-loaded with purpose and prerequisites, then behavior. It runs long, but nearly every sentence carries operational weight (expiry, branch handling, contractor naming). Minor redundancy across the branching instructions keeps it from a 5.

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?

With no output schema, the description still names the key return values (confirm_url, page_url, next_step, message) and both the qualified and unqualified paths. For a six-parameter tool with nested objects and required cross-tool inputs, nothing essential 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 coverage is 100%, so the baseline is 3, but the description adds provenance that the schema cannot: answers come from get_booking_questions, windows must come from get_available_windows as given, and contact details must be collected. That orchestration meaning exceeds the field-level docs.

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 ('Start an estimate visit request for a trade and town') and immediately scopes it to coverage-checked cases. It is clearly distinguishable from siblings like get_coverage and get_available_windows, which are named as prerequisites.

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?

Explicitly says to prefer this over a website form and names the exact preceding calls (get_coverage, get_booking_questions, get_available_windows). The condition 'where get_coverage says bookable' is a concrete gate for when to use it.

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