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

The readOnlyHint annotation already covers the safety profile, so the description does not need to restate it. It adds the GET endpoint and confirms single-record retrieval, but it does not mention error behavior, authentication, or response shape. This is acceptable given the annotation coverage.

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 two short sentences with no filler. It front-loads the core action and includes a useful endpoint reference, making every word valuable.

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 read-only getter with one required parameter, full schema coverage, and a readOnlyHint annotation, the description is sufficiently complete. The endpoint, resource, and parameter are all covered; no output schema exists, but the operation is self-explanatory.

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%, so the schema already documents opportunity_id as 'The opportunity id.' The description adds little beyond the schema, merely repeating that retrieval is by id. Baseline 3 is appropriate because the schema carries the parameter documentation burden.

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 states a specific verb and resource: 'Get a single opportunity by id.' It also includes the exact REST endpoint, making the operation unambiguous. It is clearly differentiated from sibling list tools like keap_list_opportunities and other get_* 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 implies the use case: call this tool when you already have an opportunity_id and need exactly one opportunity. It does not explicitly name alternatives or exclusion criteria, but the 'single' and 'by id' wording gives clear contextual guidance.

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