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

Beyond the annotations (which only declare readOnly=false, idempotent=false, destructive=false), the description discloses that account-scoped context is attached, that repeats are deduplicated, and that omitting description turns the call into a reply reader. That dual read/write behavior and the dedup guarantee are exactly the extra context annotations cannot convey.

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 tight sentences, front-loaded with the core action, then routing, then side effects, then the reply mode. No filler and nothing repeated from the schema 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?

With an output schema present, return values need no explanation, and the description covers routing, side effects and the read mode for a zero-required-parameter tool. It is complete enough to invoke correctly, though it says nothing about auth requirements or submission limits, minor omissions for an openWorld=false support tool.

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% so the baseline is 3, but the description adds meaning the schema lacks: it maps session_id (+ optional job_id) to the Mac case and ref_id to the build case, and clarifies that email is only for requesting a direct resolution update and that omitting description switches modes. This is useful selection logic beyond field definitions.

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 (file) plus the resource (unknown/unfixable error) and the destination (NoMac support), and immediately gives the routing rule distinguishing a Mac session (session_id/job_id) from a build (ref_id). An agent can tell this apart from the many status/get_* siblings without opening a schema.

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 scope qualifier 'unknown/unfixable error' tells the agent when this tool is warranted and implicitly when it is not (known/fixable failures). It also explains the two parameterization paths and the omit-description mode for reading replies. No sibling tool is named as an alternative, so it stops short of a 5.

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