create_partner

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

There are no annotations, so the description carries the behavioral transparency burden. It explicitly discloses the key side effect: 'grants the user read access to the whole library,' which is crucial for a mutating, security-relevant operation. It could go further by mentioning behavior on duplicate partners or reversibility, but the most important side effect is clearly stated.

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 concise and front-loaded with the main action, followed by the side effect, parameter, and return value. The 'Returns' line is slightly redundant given an output schema exists, but the overall structure is tight and every remaining sentence earns its place.

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 one-parameter tool, the description covers the action, the side effect, how to find the required ID, and the return value. It does not mention how this compares to shared links or what happens if a partner already exists, but the essential information needed to call the tool correctly is present.

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?

Although the JSON schema provides only the title 'User Id' and no description, the tool description compensates fully with 'Args: user_id: The user to share with.' It also tells the agent how to obtain a valid value ('Find the id with list_users'), giving the single parameter both meaning and provenance.

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 states a specific verb ('Share'), a concrete resource ('this account's library'), and a clear recipient ('another user on the server'). It distinguishes itself from sibling tools by explaining the result: 'The other user will see these photos next to their own.' This makes the tool's role 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?

The description gives clear context for when to use the tool—sharing with another server user—and provides a concrete prerequisite: 'Find the id with list_users.' It does not explicitly name alternatives like create_shared_link or remove_partner, but the phrasing 'another user on the server' helps disambiguate from link-based sharing.

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