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

Beyond the annotations, the description adds important behavioral context: the need to always show the user what will be changed and ask for confirmation, and the prerequisite of DEVOPS_PAT with Work Items: Write permission. These details help the agent understand safety and authorization requirements that annotations alone do not convey.

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 dense but efficient: it front-loads the core purpose, then covers supported fields, trigger phrases, safety behavior, and authorization in a concise, scannable format. 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?

For a three-parameter update tool with annotations and a fully documented schema, the description is complete: it explains what the tool updates, how fields are selected, when to trigger it, how to handle confirmation, and what permissions are required. No output schema exists, and the description does not need to explain return values for this mutation tool.

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 all parameters. The description reinforces that fields use Field Reference Names and can be standard or custom, but it largely duplicates the examples already present in the fieldsJson parameter description rather than adding substantial new parameter-level meaning.

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 specific action ('Update one or more fields on an existing Azure DevOps Work Item') and identifies the resource. It distinguishes itself from sibling tools like ado_create_task by explicitly targeting existing work items, and from read/query tools by the update verb.

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 context for when to use this tool, including user trigger phrases and the requirement to show changes and get confirmation before calling. However, it does not explicitly state when not to use it or name alternative tools such as ado_create_task for new work items, so it falls just short of full exclusion guidance.

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