CPI Get Entity (read one record by key)

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

With no annotations, the description carries the burden. It adds useful behavioral context: the distinction between single and composite keys, the raw flag for /$value endpoints, and the optional navigation follow. It implies a read-only operation ('Get'), which is accurate. It doesn't describe error handling or auth, but for a simple getter, the transparency is adequate.

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. Every word earns its place, providing examples and key distinctions without verbosity.

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?

The tool has 5 parameters, one required, no output schema. The description covers the key/keys distinction, raw behavior, and navigation, making the tool usable. It could mention error cases or return format, but these are not critical for a straightforward getter and the schema covers most parameter details.

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 80%, so baseline is 3. The description adds value beyond the schema by explaining when to use 'key' vs 'keys' with concrete examples, and clarifying the navigation parameter's purpose. It doesn't describe entitySet, but that is arguably self-evident from the tool name.

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 clearly states the tool gets a single entity by key, which is a specific verb and resource. It distinguishes itself from siblings by focusing on key-based retrieval and optional navigation, though it doesn't explicitly name alternative tools for comparison.

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 provides clear usage context: use 'key' for single-key entities and 'keys' for composite keys, and optionally follow navigation. It doesn't explicitly state when not to use this tool or name alternatives, but the guidance is unambiguous and practical.

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