session_save_image

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

No annotations are provided, so the description carries the full burden for behavioral disclosure. It explains that the image is copied into Prism's media vault, indexed in handoff metadata, and becomes visible on the next session_load_context. This sufficiently discloses the tool's effects and downstream behavior.

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?

Two sentences and no fluff. The purpose is front-loaded in the first sentence. Every sentence provides unique, actionable information without repetition.

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?

No output schema; the description explains the post-save lifecycle (media vault storage, indexing, visibility on next context load). Given the tool's simplicity and the presence of a sibling for viewing (session_view_image), the description is fully complete.

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 100%, so the description adds value beyond structural details. For the description parameter, it clarifies purpose ('What does this image show? Used for indexing'). For file_path, it repeats 'absolute or relative path' from the schema but reinforces the accepted formats. This adds helpful context.

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?

Description opens with a clear verb+resource ('Save a local image file into the project's permanent visual memory') and enumerates specific use cases (UI states, diagrams, architecture graphs, bug screenshots). This differentiates it from siblings like session_save_experience or session_save_handoff.

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 explicitly states when to use the tool ('Use this to remember UI states, diagrams...'). It does not explicitly state alternatives or exclusions, but the sibling list includes session_view_image (viewing) and session_save_experience (saving experiences), so usage context is clear.

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