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

Annotations already declare readOnly, idempotent, non-destructive, so the description's extra value is the negative guarantees: it returns choices without selecting or launching, and does not auto-start Desktop. It also implies the prerequisite that a receiving Desktop must be running. It stops short of describing the shape of the returned choices, which is a minor gap given there is no output schema.

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?

Four short sentences, front-loaded with the action and its side-effect boundary, then usage, then siblings. Nothing is redundant with the title or annotations.

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 parameterless read tool with full annotation coverage, the description supplies everything an agent needs: what it returns conceptually, what it does not do, the Desktop prerequisite, and where to go next. No output schema exists, but the return is a simple list of installation choices that is adequately characterized.

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 tool takes zero parameters, so the baseline is 4; there is nothing for the description to disambiguate. It does not waste words restating an empty schema.

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 and resource: discover installed Blender executables and versions via the running Desktop. It immediately distinguishes itself from the two sibling tools an agent might confuse it with (select_blender, get_app_state) by name.

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?

Explicitly says when to use it ('Use when choosing an installation at the user's request') and names the follow-up tools: select_blender to save the choice, get_app_state to read current selection and Desktop status. The routing is unambiguous.

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