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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds meaningful beyond-annotation context by explicitly listing what is never returned (QR codes, secrets, API keys, proxy addresses, org ids, stored metadata), which helps the agent understand the tool's safety boundary and not expect sensitive fields.

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?

Two sentences with no redundancy. The first sentence front-loads the core purpose, and the second adds a valuable boundary without padding. Every phrase 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?

Given only one parameter, a complete output schema, and safety-relevant annotations, the description covers the critical behavioral and scope information. It misses nothing essential for correct invocation; the output schema handles return-value details, so the description's exclusion list is the main added context.

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 for the single parameter is 100% and the schema already defines the instanceId format and meaning. The description adds only the 'tenant-scoped' qualifier, which is mild context but does not materially change how the parameter should be set. Baseline 3 is appropriate because the schema carries the parameter semantics.

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 uses a specific verb ('Fetch') with a clear resource ('one tenant-scoped Wapiworld WhatsApp instance') and scope ('safe operational details'). It distinguishes itself from list-oriented siblings like list_instances by emphasizing a single instance, and from get_instance_status by focusing on operational details rather than status.

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 clearly states when to use the tool: to fetch safe operational details for a single instance. It does not explicitly name alternatives or when-not-to-use conditions, but the single-instance scope and safe-details wording provide enough context for an agent to distinguish it from list_instances and get_instance_status.

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