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

Goes well beyond the readOnly/idempotent annotations by disclosing the login requirement, the absence of public image URLs, the private rendering API for card images, the instruction to share only shareText+link, and exact failure semantics (found=false and 403 cases). This is thorough behavioral disclosure.

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?

Well-structured and front-loaded: it starts with the auth requirement, then the return value and use case, and uses labeled sections for kind values, image caveats, and failure semantics. Every section contributes operational value with no 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?

Given there is no output schema, the description covers return contents, auth, kind/id combinations, an important image-sharing caveat, and failure behavior. The only notable gap is that the 'activity' enum value is not explained, so one valid invocation path remains partially unspecified.

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?

Adds substantial meaning beyond the schema, such as owner being usable for self or others, card/position/onboarding requiring id='me', and position being the only share outlet for the positioning bar. However, the enum includes 'activity' but the description does not explain it, leaving one valid kind semantically undocumented.

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 names a specific operation: return a share-card manifest containing shareText and a link, plus card metadata. It also ties the tool to a clear user scenario—helping an agent share a profile or need—making it easy to distinguish from generic getters and from send_share_card.

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 states when to use the tool: when the agent helps the user share their home page or need by fetching ready-made copy and a link for forwarding. It does not explicitly name alternatives or state when not to use it, so it falls just short of the highest bar.

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