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

Annotations already declare readOnlyHint, idempotentHint and non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context: results carry the company's own wording plus the date BackPR verified it, and the publisher has a commercial interest in the domain but is excluded from the index. It does not discuss result-set size or empty-result behavior beyond what the schema's limit implies.

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?

Front-loaded with the core action in the first clause, followed by scope, filters, use case and disclosure in that order. The opening sentence is long and heavily comma-listed, but every clause carries information an agent needs and there is no filler.

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 an output schema present, the description correctly omits return-value detail and instead supplies what the schema cannot: data provenance, staleness signaling via check dates, filter intent, and the publisher's conflict of interest. Nothing needed to select or invoke this tool correctly is missing.

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 each parameter is documented in-schema, including the free_for_nonprofits true/false/omit semantics and the limit bounds. The description's filter sentence restates rather than extends the schema, so the baseline of 3 is appropriate.

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 specific verb and resource ('Search BackPR's registration software pricing index') and enumerates exactly what the index contains: published plan prices, nonprofit offers, family fees, contract terms, with source wording and check dates. This is clearly distinct from sibling tools like find_programs, find_template and get_state_rules.

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?

Gives concrete usage context ('Use it to compare costs or find free options') and lists the three available filter axes, which maps directly onto how an agent should narrow a query. It stops short of naming alternatives or stating when not to use it, but the vendor disclosure ('BackPR publishes this index and sells registration software; BackPR isn't in the index') usefully pre-empts a bias question the agent would otherwise have to reason about.

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