Get Custom Fields

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

Annotations already provide readOnlyHint, idempotentHint, and destructiveHint, so the description's job is lighter. It adds that the tool returns 'allowed values,' which is not in annotations or schema. However, it does not disclose other behavioral traits like data source or limitations. This is adequate but not exceptional.

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 consists of two concise sentences. The first states the core purpose, and the second provides usage guidance. Every sentence adds value, with no redundancy or fluff.

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?

Given the presence of an output schema and annotations, the description provides sufficient context for the agent: it explains the tool's role in the workflow (discovery before creation/update) and its input/output nature. No critical gaps exist for the tool's simplicity.

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?

Input schema covers all 3 parameters with full descriptions, achieving 100% coverage. The description does not add new parameter semantics beyond what is in the schema. According to rules, baseline is 3 when coverage is high, and no extra value is provided.

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 retrieves available custom fields and their allowed values for a project. It uses specific verbs and resources ('Get available custom fields') and differentiates itself from sibling tools like list_custom_field_values and create_custom_field_value by emphasizing it is used to discover fields before creating or updating test cases.

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 explicitly states when to use the tool: 'Use this tool to discover what custom fields are available... essential before creating or updating test cases.' This provides clear context and implies when not to use it (when not needing discovery). It also hints at the prerequisite nature for other operations.

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