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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context: it returns only credits (no provider names, no USD in assistant copy), and it mirrors the app's Services tab. This goes beyond the annotations by clarifying the output scope and the assistant-facing constraint.

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 description is two sentences with no filler. The primary purpose and key constraint ('credits only') are front-loaded, and the routing to sibling tools is compact. Every sentence earns its place.

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?

The tool has an output schema, so return values need not be explained. The description covers the discovery workflow, the output scope, and the next steps. It does not explain pagination or sorting parameters, but for a read-only discovery tool with an output schema, the description is largely complete. The missing parameter semantics for page/limit/sortBy/sortOrder are a minor gap.

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 0%, so the description carries the burden for parameter meaning. The description mentions 'search by app/service name', which maps to the 'search' parameter, but it does not explain 'v', 'page', 'limit', 'sortBy', or 'sortOrder'. With 6 parameters and 0% schema coverage, the description only partially compensates; the baseline 3 is appropriate because it adds some meaning but leaves most parameters undocumented.

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 ('search'), a resource ('services'), and the key scope ('by app/service name'). It also distinguishes itself from siblings by noting it returns only credits, no provider names or USD, and explicitly names related tools (ucode_sms_service_detail, ucode_sms_rent_packages). This clearly differentiates it from ucode_sms_services and ucode_services_catalog.

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 explicitly says when to use this tool: as the primary discovery step by app/service name. It also names the next steps (ucode_sms_service_detail or ucode_sms_rent_packages) once service and country are chosen, providing clear routing guidance. It does not explicitly list exclusions, but the 'Primary discovery' framing and named alternatives give strong usage context.

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