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

Annotations only declare the mutation/safety profile (readOnly=false, idempotent=false, destructive=false). The description adds substantial context beyond them: the external network requirement, the raw POST contract with field names, size/format/count limits (7 photos, 10 MB, JPEG/PNG/WebP, 15-minute expiry), the returned field shape, and the crucial lifecycle note that 'Nothing is a memory until finish runs.'

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?

Front-loaded with purpose and the alternative, then the return shape, then the mechanics. Every sentence carries operational detail and none is filler, though the density is high and a couple of clauses could be tightened.

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 multi-step upload flow with no output schema, the definition compensates by enumerating the returned fields ({memoryId, endpoint, header, how, expiresAt, maxFiles}) and the exact HTTP mechanics an agent must execute. Nothing needed to invoke it correctly is missing.

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% and the single parameter (maxFiles, 1-7, default 7) is fully documented there. The description only echoes the count limit ('Up to 7 photos') without adding syntax or meaning beyond the schema, so the baseline 3 applies.

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?

States a specific verb and resource ('Save photos ... as a picture memory') and immediately scopes which photos qualify ('photos YOU can already read ... on your sandbox disk, or files in a working directory'). It explicitly distinguishes itself from the sibling muninn_picture_upload_start, so an agent can route without opening either schema.

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?

Gives an explicit condition for using the alternative: 'if your code cannot reach it, use muninn_picture_upload_start so the user picks them instead.' It also brackets the workflow by naming the follow-up calls (muninn_picture_view, muninn_picture_upload_finish), leaving nothing about when-to-use to inference.

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