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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), so the bar is lower. The description adds useful detail about what the document contains (aliases, services, verification methods) and that it works for did:web, but it omits operational traits like authentication requirements, rate limits, or error behavior that could further aid the agent.

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?

The description is a single, well-structured sentence that front-loads the core action and then efficiently packs scope, sibling comparison, and input format. Every clause earns its place with no redundancy.

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 low complexity (one parameter), the presence of annotations covering safety, and an output schema that handles return values, the description is nearly complete. The only minor gap is the absence of any note on error conditions or authentication, which could be helpful but is not critical here.

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% and the single parameter is fully documented as 'A handle or DID'. The description simply restates 'Input is a handle or DID' without adding format hints or constraints beyond the schema, so it meets the baseline without exceeding it.

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 (Fetch) and resource (raw DID document) and explicitly distinguishes itself from sibling get_profile, noting it is broader. The scope is further clarified by listing the content categories (aliases, services, verification methods) and supported DID types (did:web).

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?

Provides clear contextual guidance by contrasting with get_profile ('Broader than get_profile') and mentioning a use case (did:web accounts), which implies when to use this tool over the profile-specific one. However, it does not explicitly state when NOT to use it or offer a direct alternative for narrow needs, leaving some inference.

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