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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered without the description. The description adds useful context that the token is read-only and belongs to the CADProps preview, but says nothing about token lifetime, rotation, or what happens on an invalid ref.

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?

A single front-loaded sentence with no filler; the subject and action come first. It is appropriately sized for a one-parameter utility tool.

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 tool whose sole input is an opaque 'ref', the description omits the one thing an agent most needs: the provenance and format of that ref, plus any indication of renewal cadence or failure behavior. Annotations cover safety and no output schema exists, but the input-side gap leaves the definition under-specified.

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 0% and the single parameter 'ref' is completely undocumented in both the schema and the description. The description never explains what 'ref' is (a token id? a view id?) or where the caller obtains it, so it fails to compensate for the coverage gap.

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?

Names a specific verb (renew) and resource (the CADProps preview's read-only token), which is enough for an agent to distinguish it from convert_cad, inspect_cad, and open_in_workspace, none of which touch tokens. It stops short of explicitly contrasting itself with those siblings, so it lands at a solid 4 rather than 5.

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 only contextual clue is 'used by the CADProps preview,' which identifies a consumer, not a condition for invocation. There is no statement of when an agent should call this versus another tool, no mention of token expiry or failure conditions, and no alternatives named.

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