custom_fields_get_custom_fields_by_object_key

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds no additional behavioral context, such as whether the response is a list, requires specific authentication, or involves pagination. For a read operation, the description should at least hint at the return scope, but it is silent.

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 extremely short, but that brevity is not effective conciseness—it omits essential context. It is a single phrase that restates the tool name, carrying minimal informative value. The structure is acceptable (one line), but it does not earn its place as a useful description.

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 tool with two parameters and no output schema, the description should explain what the tool returns and when it is appropriate to use. It does neither. While annotations cover the safety profile, the description leaves the agent without understanding the data returned or how this tool fits into custom fields workflows.

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 both parameters are already documented in the schema, including the objectKey prefix requirement and the locationId default. The description adds no parameter information beyond the schema, so it performs at the baseline of 3 for high schema coverage.

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 'Get Custom Fields By Object Key' is essentially a restatement of the tool's name. It clarifies the verb and resource but adds no detail about what custom fields are, what an object key represents, or what the tool returns. It fails to distinguish this tool from siblings like custom_fields_get_custom_field_by_id, which also retrieves custom fields but by ID.

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?

There is no guidance on when to use this tool versus alternatives. No mention of use cases, prerequisites, or differences from sibling tools. An agent cannot determine whether to choose this or custom_fields_get_custom_field_by_id without opening schemas.

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