Completions at a source offset

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

The annotations already establish that this is a read-only, idempotent, non-destructive, non-open-world operation. The description adds useful context by naming the kinds of completion items and comparing them to an editor language server, but it does not describe return shape, limits, or other behavioral details beyond that.

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 purpose is front-loaded in a single efficient sentence, followed by a short contextual tag. The trailing 'For structured or assisted authoring' is vague and adds little, keeping it just below top conciseness.

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 simple two-parameter, read-only tool with full schema coverage and annotations, the description is largely sufficient. It explains the kinds of items returned and the offset-based scope, though without an output schema it could be more explicit about the exact return structure.

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%, and both parameters are documented in the schema. The description reinforces the byte-offset semantics and source context, but it adds no syntax or format guidance beyond what the schema already provides, so the baseline of 3 is appropriate.

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 ('List') and resource ('completion items in scope at a source byte offset') and even enumerates item categories. It does not, however, distinguish itself from likely sibling tools such as finish or suggest, so an agent still has to infer the boundary.

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 phrase 'For structured or assisted authoring' implies a usage context, but it gives no explicit when-to-use guidance, no exclusions, and no comparison to siblings like finish, suggest, or fix.

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