Set Login URIs

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

Annotations indicate the tool is not read-only and not destructive. The description adds context by explaining the merge/replace behavior, which is beyond what annotations provide, but does not mention error conditions or prerequisites.

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?

Three sentences with no fluff. First sentence front-loads the purpose, second explains mode, third lists match values. Every sentence adds value.

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 description covers essential behavior for a low-complexity tool. It lacks return value information, but given no output schema, it does not hinder use. Could mention return or error cases.

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 description adds minimal new info beyond the schema. It summarizes mode and match values, but schema already details them. Baseline 3 is appropriate.

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 it 'Set or update the URI list on a login item.' The verb 'set/update' and resource 'URI list' are specific, and the mention of modes differentiates it from sibling tools like keychain_get_uri.

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 explains when to use each mode ('replace overwrites the full list; merge updates existing URIs and adds new ones'), but does not provide guidance on when to choose this tool over alternatives like keychain_update_item.

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