open_lens

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

No annotations are provided, so the description carries the full behavioral burden. 'Working copy' hints at session state, but it never says whether the underlying file is modified, whether the copy must later be released via close_session, whether repeated opens are allowed, or what permissions are needed. For a state-creating operation this is a significant gap.

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?

One compact sentence, front-loaded with the action and resource, followed by the returned data. No padding or redundancy.

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?

An output schema exists, so return values need not be re-explained, and the description correctly enumerates the returned categories. However, for a session-opening tool with no annotations and a documented sibling (close_session), the lifecycle and file-safety context an agent needs is absent.

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% and the single required 'path' parameter is never explained. The mention of a '.len 镜头文件' does implicitly signal the expected file type, which gives partial meaning, but format, absolute-vs-relative path, and error behavior are all unaddressed.

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 gives a specific verb ('打开' / open) and a specific resource (a working copy of a .len lens file), and lists what the call surfaces (surfaces, materials, units, wavelengths, fields). This distinguishes it reasonably from create_lens and get_lens, though it never explicitly names an alternative sibling. It is clear but lacks the explicit sibling differentiation that would earn a 5.

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?

There is no when-to-use guidance, no statement of when to prefer this over create_lens, get_lens, or open-a-new-session flows, and no mention of prerequisites or the close_session lifecycle. The agent is left to infer the correct moment to call it.

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