hub_card_set

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 discloses the upsert nature ('Create or update') and the preservation of hand-written frontmatter and Facts, which is valuable. However, it does not mention return format, error handling, permissions, or whether other fields are overwritten, leaving some behavioral ambiguity.

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 three sentences with no redundant wording. It front-loads the core purpose, then adds usage context and a key behavioral guarantee, making it highly efficient and easy to parse.

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 3-parameter tool with no output schema, the description covers the primary purpose, when to use it, and a notable behavior (preserving frontmatter/Facts). It stops short of describing return values or edge cases, but the provided context is sufficient for an AI agent to select and invoke the tool correctly in typical scenarios.

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 coverage is 100%, so the baseline is 3. The description adds extra semantics for 'project' by noting 'no folder needed' and implies 'digest' is the current state via 'a name and a digest', but does not elaborate on the 'by' parameter, which is fully covered by the schema's existing description.

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 tool's action ('Create or update a project card') and its key inputs ('name and digest'). It explicitly differentiates from sibling hub_sync by noting 'no folder needed', and provides a concrete example use case ('when harvesting a dialog'), making the purpose unambiguous.

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 gives explicit usage guidance: 'Use it to capture a project that is not a local git checkout' and names the alternative tool (hub_sync) with a contrast ('unlike hub_sync'). The example of harvesting a dialog further clarifies when to choose this tool over siblings.

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