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

With no annotations provided, the description must carry the burden of behavioral disclosure, but it only names the WebFinger protocol. It does not mention whether the operation involves network access, possible failure modes, authentication requirements, rate limits, or what kind of result to expect beyond the bare resolution step.

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 concise phrase with no filler. It front-loads the tool name and immediately states the action and input format, making it easy to scan.

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?

The tool is simple with one parameter and an output schema, so the core invocation is reasonably covered. However, the absence of usage guidance and behavioral context (errors, network behavior, relationship to the 'webfinger' sibling) leaves meaningful gaps for an agent deciding whether and how to call it.

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 input schema has one parameter 'q' with no description, so schema coverage is 0%. The phrase 'user@instance' strongly implies the expected format for the query, which partially compensates, but the description never explicitly states that 'q' takes that value or provides an example.

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?

The description uses a specific verb ('Resolve') and resource ('user@instance via WebFinger'), so an agent can tell this is a Mastodon account lookup rather than a general utility. It does not explicitly contrast with the sibling 'webfinger' tool, but the Mastodon-specific framing is enough to avoid direct confusion.

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?

No guidance is given about when to use this tool instead of alternatives such as the generic 'webfinger' sibling. The context is implied by the name and phrasing, but there are no explicit conditions, exclusions, or when-not-to-use instructions.

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