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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, openWorldHint, destructiveHint=false), so the bar is lower. The description still adds real value by disclosing coverage scope — records outside public listings are returned here — which tells the agent this tool can succeed where a listing search returns nothing.

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?

Two sentences, front-loaded with the core purpose and scope caveat second. The Hebrew sentence duplicates the English content, which costs space for monolingual readers but is defensible given the Israeli nonprofit domain.

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 carries the return-value burden and does state the result is a 'Full registry record.' Combined with annotations that fully cover the safety profile and a 100%-documented single parameter, this is close to complete; a brief note on the record's shape would make it airtight.

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% and the single parameter's format (string pattern or integer) is fully documented in the schema. The description only restates that lookup is by registration number, adding no syntax or formatting detail 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+resource ('Full registry record for one Israeli nonprofit') and the exact lookup key ('by registration number'). It is cleanly distinguishable from siblings like get_company and get_partnership by entity type and identifier, so an agent needn't open schemas to pick it.

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?

Usage is implied: use this when you have a registration number and need the complete record rather than a listing. The line 'Includes nonprofits that are not in the public listings' hints at an advantage over search/list tools, but it never explicitly says when to prefer this over search_companies or list_marketplace_listings, nor that a registration number is required first.

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