session_open

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

No annotations are provided, so the description carries the full burden. It does disclose a meaningful behavioral trait: the file is opened into an isolated copy so source files are never edited in-place. But it omits session lifecycle, error behavior for a missing/invalid path, and persistence semantics, which matter given the surrounding session_* tools.

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?

A single front-loaded sentence carrying the action, target, and the key safety benefit with no wasted words.

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 presence of an output schema means return values need not be explained. Still, for a tool sitting among session_create/session_close/session_list, the description omits how the session must be managed afterward, leaving a notable lifecycle gap.

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 coverage is 0% with one required 'path' parameter. The description only loosely compensates by implying path points to an existing image or XCF file; it adds no format, extension, or validation detail beyond that weak hint.

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+resource (open an existing image/XCF) plus the core behavior (isolated session copy). The word 'existing' implicitly separates it from session_create, but it never explicitly names or contrasts the sibling, so the differentiation is inferable rather than stated.

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?

Usage is implied: use this to load a file for editing rather than creating a new session. However, there is no explicit when-to-use/when-not guidance and no reference to the obvious alternative (session_create) or to the required follow-up (session_close), leaving lifecycle decisions to inference.

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