snapshot

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

The description goes beyond annotations by specifying which fields are omitted (account identifiers, linked images, persona) and highlighting the versioned nature of the snapshot. This useful context is not present in the annotations, and there is no contradiction.

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 two concise sentences, front-loaded with the main action, and contains no redundant information. Every word adds value.

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 single-parameter tool with output schema and rich annotations, the description covers the key return behavior and privacy filtering well. However, the unclear 'ref' parameter and lack of usage guidance leave minor gaps, preventing a perfect score.

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 only parameter 'ref' is completely undocumented in the schema, and the description does not explain what 'ref' refers to. With 0% schema coverage and no compensating description, the agent lacks essential parameter 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 identifies the action ('Observe a public character once') and the return type ('CharacterSnapshotV1'), with specific details about privacy filtering and omitted fields. This distinguishes it from sibling tools like derive or diff, making its 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?

The description implies a read-only, one-time snapshot use case but does not explicitly compare with alternatives or state when not to use. It lacks explicit alternatives or exclusions, so the agent must infer when to choose this over siblings.

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