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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false; the description adds genuinely useful context beyond that: omitted fields retain stored values, sent tags replace the whole list, and pages using the asset are unaffected. It also notes the description field feeds list_assets search, a non-obvious downstream effect. It does not cover permissions or the response shape.

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 tight sentences, front-loaded with the action and scope, then the update semantics, then the non-effects. No filler; the only mild overlap is the tags-replacement clause, which is also in the schema, but it earns its place by reinforcing merge-vs-replace.

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 4-parameter partial-update tool with full schema coverage and no output schema, the description covers intent, prerequisites, merge semantics and side effects. The only gap is the return value/confirmation behavior, which is minor given annotations already flag idempotency.

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 baseline is 3; the description exceeds it by explaining patch semantics ('a field you leave out keeps its stored value') and the replace-not-merge behavior of tags, neither of which the bare schema states. It also frames what 'description' means semantically (what the image shows) and that it is searchable.

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+resource (change description or tags of an asset in the media library) and immediately bounds the scope by declaring what does NOT change: the file, its name and url. That lets an agent distinguish it from upload_asset and other mutators without inspecting schemas.

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?

Points the agent at list_assets to obtain the id, which is the key prerequisite for invocation. It also clarifies what the tool is not for (renaming, replacing files). It stops short of naming an explicit alternative for those excluded operations, so no exclusion routing to a sibling is given.

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