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

Annotations already declare destructiveHint=true, idempotentHint=true, openWorldHint=true, and readOnlyHint=false. The description adds meaningful context beyond that — credentials travel in plain text, tokens must never be invented or reused, and the update only takes effect on the next import/build while running containers are untouched — but does not cover permissions/ownership requirements or error behavior, keeping it at a solid 3 rather than higher.

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?

Three short paragraphs, well front-loaded with the mutable-field list followed by safety and workflow guidance. Every sentence earns its place, though the response-format and workflow notes could be tightened slightly.

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?

With no output schema, the description usefully tells the agent what the response contains (auth mode, not the secret) and how the change propagates (next import/build). For a 9-param destructive mutation with a nested auth object it is nearly complete, missing only permissions/error detail.

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 100%, including the nested auth object with per-field descriptions, so the schema carries the bulk of parameter meaning and the baseline is 3. The description reinforces the auth semantics (response reports auth mode, never the secret) and the preview convention, but adds little syntax or format detail beyond what the schema already provides.

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 (Edit) and resource (image source), enumerates the mutable fields (name, description, identifier, builder integration, registry credentials), and explicitly bounds the operation by naming what cannot change (the origin/registry/target). It also implicitly distinguishes itself from list_image_sources and delete_image_source by naming the edit surface.

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 when-to-use workflow (call with preview:true, confirm with the user, then call again without preview) and a when-not-to alternative (create a new source to change the origin). It also advises preferring webhook auth or dashboard-managed auth when the user has a choice, which is actionable guidance rather than vague context.

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