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

Annotations indicate readOnlyHint=false, so a mutation is expected. The description adds the side effect 'resets humidity tracking', which is useful context. However, it does not disclose whether the dried_at parameter is required to overwrite the timestamp or if it defaults to the current time, nor any other behavioral nuances.

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 one concise sentence that front-loads the action and outcome without any filler. Every word contributes to understanding the tool's purpose.

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 mutation tool, the description covers the primary effect but omits parameter semantics (especially dried_at) and any prerequisites or error conditions. Given the moderate schema coverage and absence of an output schema, more contextual details would improve completeness.

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?

The schema provides a description for filament_id (though the comma-separated note conflicts with its integer type) and no description for dried_at. The tool description adds no parameter information, leaving the meaning and format of dried_at unclear. With only 50% schema coverage, the description should have compensated.

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 action ('mark'), the resource ('filament spool'), and the outcome ('freshly dried'), including a distinctive side effect ('resets humidity tracking'). This differentiates it from related tools such as assign_filament or adjust_filament_weight.

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 implies the tool is used after drying a spool, but it does not explicitly state when to use it versus alternatives, nor does it mention any exclusions or prerequisites. The guidance is purely implied by the phrasing.

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