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

The description discloses meaningful behavioral traits absent from the annotations: criteria reuse, lack of refinement support, specific refusal conditions, and clamp behavior with a `clamp_notice` to surface. This goes well beyond the minimal readOnly/destructive hints and tells the agent what to expect at runtime.

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 densely informative with no filler. It front-loads the core action, then covers exclusions, alternatives, refusal conditions, and edge-case behavior in a compact, logically ordered block that earns each sentence.

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 3-parameter tool with no output schema, the description covers invocation semantics, failure modes, clamping behavior, and user-facing notices. The only minor gap is that it does not explicitly describe the success return payload, but the tool's purpose and schema make that reasonably inferable.

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. The description adds value beyond the schema by explaining that additional_count is clamped when balance covers fewer results and that list_name should be a fresh slug when starting a new list. This enriches the static schema definitions.

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 opens with a specific verb and resource: 'Add more results to a named list on an agent.' It clearly distinguishes itself from the sibling start_find_search by noting it reuses the list's original criteria and does NOT support refinement, so an agent can tell what this tool is for immediately.

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?

Provides explicit routing guidance: if the user wants to narrow criteria, tell them to start a new list via start_find_search with a fresh list_name. It also lists concrete refusal conditions, giving clear when-not-to-use context beyond what any schema or annotation conveys.

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