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

Beyond the readOnly/idempotent annotations, the description adds useful behavioral context: the search covers a public cash-pay catalog, prices are sticker prices, and every order incurs a $6 processing fee. This helps the agent interpret results and avoid misquoting totals.

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?

Three sentences: scope, return fields, and caveat with a pointer to quote_order. Every sentence carries information, and the most important scoping facts are front-loaded.

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 enumerates the key returned fields (name, slug, per-lab prices, sample, fasting, turnaround, order URL). It covers pricing caveats and routes to the appropriate sibling for all-in totals, so an agent has enough to invoke correctly.

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 the parameters are already documented. The description restates search dimensions already present in the query and category parameter descriptions and adds no new parameter-level semantics beyond that baseline.

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?

Description uses a specific verb ('Search') and resource ('TestWell's public catalog of cash-pay lab tests and panels'), and names the search dimensions (keyword, biomarker, CPT code, category) plus return fields. This clearly distinguishes it from siblings like quote_order and list_panels.

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?

It states that this tool returns sticker prices and explicitly directs agents to quote_order for all-in totals, giving a concrete when-to-use-this-other-tool condition. The 'public catalog' qualifier also implies this is not for find_draw_sites, lookup_reference_range, or other specialized tools.

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