linear_updateIssueCustomField

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

The description discloses the key behavior of clearing with null, which is important. However, no annotations are provided, so the description carries the full burden. It does not disclose other behavioral traits like idempotency, required permissions, or error scenarios. It is adequate but not comprehensive.

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 concise: two sentences with no wasted words. It front-loads the purpose and immediately provides the key usage detail (null to clear). Every sentence earns its place.

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 simplicity of the tool (3 parameters, no output schema), the description is mostly complete. It explains the core operation and the special value. However, it lacks details on error handling or prerequisites, but for a straightforward update, it is sufficient.

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 explains each parameter. The description adds the nuance that passing null clears the field, which reinforces the schema. Since the schema is already rich, the description adds marginal value, meeting the baseline of 3.

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's purpose: to set or clear a custom field value on an issue. It distinguishes from sibling tools like linear_updateIssue by specifying 'custom field'. It also clarifies that passing null clears the field, which is specific and helpful.

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 implicitly tells when to use: when you need to modify a custom field on an issue. It does not explicitly mention alternatives or when not to use, but the context is clear given there is a sibling linear_updateIssue for standard fields. A slightly higher score would require explicit guidance.

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