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

Annotations (readOnlyHint=false, destructiveHint=false) already indicate a non-read-only, non-destructive write. The description adds significant context: partial update semantics, immutable identity-like fields, return type ('full updated/created object'), and active Space scoping. This goes beyond annotations without contradicting them.

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 sentences, each dense with useful information: the action, mutable/immutable fields, return behavior, and Space scoping. No filler or repetition. Front-loaded with the primary purpose.

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?

Given the tool has no output schema, the description appropriately states it 'Returns the full updated/created object.' It handles nested objects by referencing the OpenAPI spec, and covers the Space scoping nuance. This is sufficient for a moderate update operation with 3 parameters.

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?

The schema covers 67% of parameters, naming body fields but deferring nested shapes to the OpenAPI spec. The description adds value by enumerating the updatable fields and explicitly calling out identity-like fields as immutable, which prevents users from passing invalid parameters. This practical guidance exceeds the schema alone.

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 'Partial update of an asset' and explicitly lists the mutable fields (name, altText, tags, metadata, status, width, height). This clearly differentiates it from create_asset, delete_asset, and get_asset. The immutable fields are named, further clarifying the scope.

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 provides concrete guidance on Space scoping: 'see set_active_space to switch, or pass space_id to override for this one call.' It also warns about immutable fields, preventing misuse. It does not explicitly contrast with sibling update tools, but the partial-update wording implies when to use it.

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