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

Annotations already declare readOnlyHint and openWorldHint, so the safe-read profile is covered. The description adds non-obvious operational detail beyond that: per-call pricing ($0.002 USDC), the x402 payment rails (Base, Solana, Arc), and that failed calls are not charged. Remaining gap is nothing about rate limits or response size, so not a 5.

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?

Information is front-loaded: source, verb, returned fields, exclusions, then pricing. It is dense but every clause carries signal; the returned-field list is slightly redundant given the output schema but is not wasteful 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?

For a 2-parameter read-only lookup with an output schema, the description covers source provenance, scope exclusions, and billing behavior. The output schema handles return values, though the description repeats them; nothing essential for calling the 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 both parameters are documented in the schema. The description only echoes the name-query behavior ('Hebrew or English name') already captured by the q description, adding no format or range guidance beyond the schema, so the 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 specific verb and resource: 'searches companies' against the 'Israel Companies Registrar (Ministry of Justice open data, data.gov.il)'. It also scopes the dataset by naming the returned fields and explicitly excluding financials and officers, so an agent can distinguish it from the other country-registry siblings.

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?

Clear usage context: query by company name in Hebrew or English, and the source is the official Israeli register. It gives useful boundaries ('Public register extract; no financial data, no officers'), which implicitly routes agents needing officers or financials elsewhere, but it does not name an alternative tool.

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