fossa_list_package_labels

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

Beyond the readOnlyHint and openWorldHint annotations, the description adds meaningful context: the package labels vs project labels distinction, the id semantics for downstream tools, and the 402/403 response on the Free plan. This enriches the agent's understanding without contradicting the annotations.

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?

Four short sentences, each earning its place: the core action, read-only confirmation, distinction from sibling, id usage, and a pricing/access caveat. No redundancy or fluff; the description is tightly written and front-loaded.

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 what the tool returns (all package labels), how it differs from the related project-label tool, what the output is used for (label_id for assignments), and a known error condition. With an output schema present and no parameters, the description is fully sufficient for an agent to select and invoke the tool correctly.

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 tool has zero parameters, so the schema provides no parameter documentation. The description adds no parameter details (since none exist), but it does clarify that the returned numeric id is the label_id used by assignment tools, which indirectly explains how the tool's output feeds into other operations. With 0 params, baseline 4 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 opens with 'List every package label defined in the organization,' a specific verb+resource+scope that immediately conveys the tool's function. It also distinguishes this tool from the sibling fossa_list_organization_labels by clarifying the difference between package and project labels.

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?

It explicitly tells the user when to choose an alternative: 'use fossa_list_organization_labels for the labels that tag projects.' It also explains that the numeric id from this tool is what assignment tools take as label_id, providing clear contextual usage guidance.

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