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

With no annotations, the description carries the full burden. It discloses a key behavior: no duplication, each entry mints exactly one card, and cards are referenced by key. This gives the agent important insight into side effects and uniqueness guarantees. It does not cover all potential edge cases (e.g., conflicts, permissions), but for a creation tool it is fairly transparent.

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 a single sentence, front-loaded with the verb and resource, and communicates the core behavior and uniqueness policy in a compact, readable format. Every phrase adds value without unnecessary filler.

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 tool is relatively simple (2 params, no output schema), but the description omits key details such as what happens when the key already exists (does it extend?), whether cards are optional, and what the return value is. The no-duplication rule is covered, but parameter roles and lifecycle behaviors are incomplete.

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 0%, so the description must compensate. It mentions 'key' and 'cards' only indirectly ('referenced by key', 'each entry mints ONE card') but does not clearly define what 'key' represents (study key vs. card key) or how the 'cards' array maps to entries. The relationship between parameters is ambiguous, leaving the agent uncertain about required semantics.

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 function with a specific verb and resource: 'Create/extend a shared study' and adds a definitive behavioral detail: 'each entry mints ONE card that lives once and is referenced by key; no duplication.' This distinguishes it from sibling tools like study_find, study_import, and study_export.

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 provides clear context for when to use this tool (creating or extending a shared study). It implies that this is the write/creation tool compared to read/search siblings, though it does not explicitly state exclusions or alternatives. This is acceptable given the obvious contrast with study_find and study_import.

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