spool_add

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

No annotations are provided, so the description carries the full burden. It usefully discloses downstream behavior (the scheduler checks fit and subtracts usage after each print) and that slot loading is an optional immediate side effect. It omits permissions, idempotency/duplicate handling, and persistence scope, which for a 9-parameter write tool is a real gap.

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?

Two tightly written sentences with zero filler. The primary action is front-loaded and the optional slot behavior is correctly relegated to a trailing clause.

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?

With no output schema and no annotations, the description must carry more weight. It covers purpose and downstream effects adequately but leaves undefined what happens on duplicate registration, whether slot assignment fails independently, and any permission requirements for a tool whose side effects reach the print scheduler.

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 78%, so the schema already documents most parameters (slot ranges, weight units, RRGGBB color). The description adds only a high-level note about weight and slot loading, contributing little semantic detail beyond the schema. 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?

States a specific verb and resource ('Register a filament spool') and goes further by naming its downstream purpose: the scheduler uses the weight to check job fit and to decrement usage. It does not explicitly distinguish itself from the nearby spool_update / spool_assign siblings, which is the only thing keeping it out of the 5 range.

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 clause 'Optionally load it into a printer slot right away' implies when to pass a slot versus not, which is useful implied guidance. There is no explicit statement of when to use this tool instead of spool_update or spool_assign, so usage remains inferred rather than stated.

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