Get Entity

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds useful behavioral context: returning the same shape regardless of which identifier is supplied, and noting the free Developer tier. No contradiction with annotations exists.

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?

The description is compact and front-loaded, with a clear opening sentence followed by a concise bulleted parameter guide. Every sentence adds value, including the 'one tool, not two' clarification and the same-shape guarantee. No filler or redundant restatement of the name/schema.

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 simple two-parameter lookup with a comprehensive output schema and clear annotations, the description covers everything needed to invoke the tool correctly: identifier sources, the exactly-one rule, the free-tier context, and response consistency. The absence of explicit not-found behavior is acceptable given the openWorldHint and output schema.

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 0%, so the description carries full responsibility for explaining parameters. It does so excellently: uei is defined as a 12-character Unique Entity ID with source fields from other tools, and cage_code is sourced from contract/award records. It also clarifies the exactly-one-parameter constraint, which the nullable schema alone does not convey.

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?

The description uses a specific verb and resource: 'Get one SAM entity's full registration record by UEI or CAGE code.' It also explicitly addresses the apparent duplication by noting that UEI and CAGE are two keys for the same question, which distinguishes this from being misread as two tools. This clearly separates it from sibling entity search/lookup tools.

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 description clearly states when to use this tool: when you need a full SAM entity record and already have a UEI or CAGE code. It also gives concrete source guidance for each identifier, e.g., UEI from search_entities/search_companies and CAGE from contract/award records. It does not explicitly enumerate exclusions or when to prefer another tool, but the guidance is strong and actionable.

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