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

Annotations already cover readOnly, idempotent, non-destructive and closed-world behavior, so the description just needs to add context — and it does: it discloses the provenance model (clinics' own website wording) and that every answer carries the clinic's own words, its page and the date it was read. The caveat that clinic-stated acceptance does not guarantee IVF coverage is genuinely useful behavioral framing beyond the annotations.

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, each carrying distinct information (what, scope, caveat) with no filler. The opening sentence is an overlong run-on with the network list interrupting the main clause, which slightly slows the front-loading, but nothing is redundant.

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 only two parameters, no output schema and annotations carrying the safety profile, the main risk is unknown return shape — which the description addresses by specifying that each answer includes the clinic's own words, page and read date. Only minor gaps remain (result volume, ordering, or how partial plan names match).

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% and the state and plan parameters are already documented with examples in the schema. The description adds only light meaning — 'one state' scope and 'optionally only the clinics that name one plan' as the filter semantics — without adding plan-matching rules (exact vs partial name, aliases such as TRICARE). 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 concrete verb and resource: the insurers and fertility benefits (Progyny, Carrot, WINFertility, Maven, Aetna...) that US fertility clinics name on their own websites as in network or accepted, scoped to one state. It is clearly a clinic-attested coverage directory rather than a rules database, which implicitly separates it from ivf_insurance_rules, but no sibling is named explicitly.

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 phrase 'for one state, optionally only the clinics that name one plan' explains how to drive the parameters, not when to pick this tool. The closing caveat ('A plan a clinic takes can still leave IVF out: the plan's own fertility benefit decides that') nudges the agent toward a rules tool for actual IVF benefit questions, but only indirectly — there is no explicit when-to-use or when-not-to-use statement.

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