unit_count

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

No annotations are provided, so the description carries the disclosure burden. It usefully discloses the ownership scope ('owned by the current user') and implies a read-only count operation. However, it does not state the return format or clarify whether the optional contains filter affects the count, leaving some behavioral details implicit.

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?

A single sentence of nine words conveys the operation, resource, and scope with no redundancy or filler. Every word 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 simple one-optional-parameter count tool, the description plus schema is largely sufficient. It covers what is counted and whose units are counted. The main gap is the lack of an explicit output format, but 'count' strongly implies a numeric result, so the definition is still reasonably complete.

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%: the contains parameter is already documented as a case-insensitive code substring filter. The description adds no additional parameter semantics, so the baseline of 3 applies.

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 states a specific verb ('Get') and resource ('count of units'), and clearly scopes the operation to units 'owned by the current user.' This distinguishes it from sibling tools like unit_list, which would return record details rather than a count.

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 gives clear context: use this tool when you need a count of the current user's units. It does not explicitly mention alternatives or exclusions, but the count-versus-list distinction is clear enough from the description and naming pattern among siblings.

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