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

Goes well beyond the annotations (readOnlyHint=false, openWorldHint=true, destructiveHint=false) by disclosing that the call fails on accounts lacking the paid add-on, that confirmation is on by default and can be toggled, and that an API key with app access is required. This is exactly the kind of failure-mode and auth context an agent needs.

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?

The leading title fragment 'Service Autopilot: Text message to a client with 2-Way Texting' is redundant with the name/title, and the confirmation requirement is stated twice ('By default you confirm each call' and 'confirm with the user before each call'). Useful content, but it could be tightened.

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 covers the essential prerequisites (add-on, API key, confirmation) an agent needs to call correctly. It is only slightly short of full coverage for a send operation, e.g. it doesn't mention delivery/return behavior.

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 client_id and message are already documented in the schema (including 'Client ID from search_clients'). The description adds no syntax, format, or length guidance beyond the schema, so the baseline 3 applies.

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 ('Sends a text to one client') and names the mechanism (Two-Way Texting), which cleanly separates it from estimate/invoice sending siblings. The reader knows exactly what the tool does without opening the 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?

Explains the precondition (account must have the Two-Way Texting add-on, else the call fails), the confirmation workflow, and that it reaches other people. It gives clear context but does not name an explicit alternative tool for users who want to message by other channels.

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